[0001] The present invention relates to a wireless communication apparatus including an
antenna.
[0002] A mobile telephone apparatus, when used for talking, is positioned near the head
of the user. If a radiation pattern of an antenna built in the mobile telephone apparatus
has such a pattern as to have a peak toward the vicinity of the user's head, the radiation
characteristics of the antenna would greatly be affected and varied, for example,
by the presence of the user's head that is present near the mobile telephone apparatus.
[0003] Jpn. Pat. Appln. KOKAI Publication No. 2002-9534 (Document 1) and Jpn. Pat. Appln.
KOKAI Publication No. 2001-339215 (Document 2) disclose prior-art techniques for overcoming
this drawback.
[0004] FIG. 1 is a perspective view showing the structure of a mobile telephone apparatus
disclosed in Document 1.
[0005] This mobile telephone apparatus has an antenna 2 that is built in a casing 1. The
antenna 2 is configured such that a dipole antenna 3 and an opposed element 4 are
arranged to be substantially parallel to each other. The direction of arrangement
of the dipole antenna 3 and opposed element 4 is substantially perpendicular to the
front surface of the casing 1 (the surface on which a receiver 5 is disposed). The
distance between the opposed element 4 and the front surface of the casing 1 is greater
than that between the dipole antenna 3 and the front surface of casing 1. Power is
fed to the dipole antenna 3 from power feed means 6. Thereby, the dipole antenna 3
functions as a dipole antenna. The opposed element 4 is a parasitic element.
[0006] FIG. 2A and FIG. 2B show radiation patterns of the antenna 2 shown in FIG. 1.
[0007] As shown in FIG. 2A and FIG. 2B, by virtue of a coupling function between the dipole
antenna 3 and opposed element 4, the antenna 2 has such a directivity as to have a
peak in a direction from the dipole antenna 3 toward the opposed element 4. In other
words, the antenna 2 has characteristics of directivity toward the rear side of the
casing 1. Therefore, the effect of the human body, which is present near the front
surface of the casing 1, can be reduced.
[0008] Document 2, on the other hand, discloses an antenna comprising a pair of a dipole
antenna and a parasitic element and another pair of a dipole antenna and a parasitic
element. The two pairs are arranged such that the parasitic elements are sandwiched
between the dipole antennas, or vice versa. By feeding power to the dipole antennas
in opposite phases, the amount of current on the PCB-GND flowing in the casing of
the wireless apparatus is reduced and degradation in characteristics due to the effect
of the human body is alleviated.
[0009] In the antenna disclosed in Document 1, however, the distance between the dipole
antenna 3 and opposed element 4 needs to be sufficiently reduced in order to obtain
the radiation pattern characteristics shown in FIG. 2A and FIG. 2B, while maintaining
impedance matching between the power feed circuit and the antenna. The following document
teaches that this distance needs to be 9/100 of wavelength or more: Tay, Balzano,
Kuster, "Dipole configurations with strongly improved radiation efficiency for hand-held
transceivers", IEEE Trans. On Antennas and Propagation, Vol. 46, June 1998, pp. 798-806.
This distance is 13.5 mm even where the frequency is 2 GHz. The distance becomes greater
in a lower frequency band. Consequently, it becomes necessary to increase the width
of the casing 1 in the front-and-rear direction, i.e. the thickness of the casing
1.
[0010] In the invention of Document 2, the two pairs of dipole antennas and parasitic elements
are provided, and power needs to be fed to both the dipole antennas in the two pairs.
In terms of circuitry scale and mounting of components, this invention is not suited
to miniaturization.
[0011] Japanese Patent No. 3356363 (Document 3) and Jpn. Pat. Appln. KOKAI Publication No.
2002-344222 (Document 4) disclose techniques for broadening frequency characteristics.
[0012] However, the techniques disclosed in Document 3 and Document 4 are unable to prevent
variation in antenna radiation characteristics due to the effect of the presence of
the head, etc.
[0013] The object of the present invention is to provide a mobile phone apparatus including
an antenna that is capable of suppressing radiation in a specific direction and can
efficiently be included in a thin shaped casing.
[0014] According to first aspect of the present invention, there is provided a wireless
communication apparatus that performs wireless communication, the apparatus having
a casing with a first surface, an external dimension of the casing in a direction
perpendicular to the first surface being less than an external direction of the casing
in another direction, the wireless communication apparatus characterized in that comprising:
a dipole antenna including a first base portion; and an opposed element formed of
a conductor material and including a second base portion, the dipole antenna and the
opposed element being disposed within the casing such that the dipole antenna and
the opposed element extend in an imaginary plane that is substantially parallel to
the first surface, and the first base portion and the second base portion are opposed
to each other.
[0015] According to second aspect of the present invention, there is provided a wireless
communication apparatus that performs wireless communication, the apparatus having
a first casing and a second casing that are coupled to each other, the first casing
having a first surface and such a shape that an external dimension of the first casing
in a direction perpendicular to the first surface is less than an external direction
of the first casing in another direction, and the second casing having a second surface
and such a shape that an external dimension of the second casing in a direction perpendicular
to the second surface is less than an external direction of the second casing in another
direction, the wireless communication apparatus being characterized by comprising:
a dipole antenna including a first base portion, the dipole antenna being disposed
within the first casing such that the dipole antenna extends in an imaginary plane
that is substantially parallel to the first surface and the second surface; and an
opposed element formed of a conductor material and including a second base portion,
the opposed element being disposed within the second casing such that the opposed
element extends in the imaginary plane and the second base portion is opposed to the
first base portion.
[0016] According to third aspect of the present invention, there is provided a wireless
communication apparatus that performs wireless communication, the apparatus having
a first casing and a second casing that are coupled to each other, and a flexible
board that electrically connects the first casing and the second casing, the first
casing having a first surface and such a shape that an external dimension of the first
casing in a direction perpendicular to the first surface is less than an external
direction of the first casing in another direction, the wireless communication apparatus
being characterized by comprising: a dipole antenna including a first base portion,
the dipole antenna being disposed within the first casing such that the dipole antenna
extends in an imaginary plane that is substantially parallel to the first surface;
and an opposed element formed of a conductor material and including a second base
portion, the opposed element being disposed on the flexible board such that the second
base portion is opposed to the first base portion.
[0017] This summary of the invention does not necessarily describe all necessary features
so that the invention may also be a sub-combination of these described features.
[0018] The invention can be more fully understood from the following detailed description
when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view showing the structure of a mobile telephone apparatus
disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2002-9534;
FIGS. 2A and 2B illustrate radiation patterns of the antenna shown in FIG. 1;
FIG. 3 shows the structure of a mobile telephone apparatus according to a first embodiment
of the present invention;
FIG. 4 illustrates a state in which electric current occurs in the antenna shown in
FIG. 3;
FIG. 5 illustrates a radiation pattern of the antenna shown in FIG. 3;
FIG. 6 shows a relationship between a distance, on the one hand, which lies between
the dipole antenna and opposed element shown in FIG. 3, and a difference, on the other
hand, between a maximum value and a minimum value in the antenna radiation pattern;
FIG. 7 shows the structure of a mobile telephone apparatus according to a second embodiment
of the present invention;
FIG. 8 illustrates a radiation pattern of the antenna shown in FIG. 7;
FIG. 9 shows the structure of a mobile telephone apparatus according to a third embodiment
of the present invention;
FIG. 10 illustrates a state in which electric current occurs in the antenna shown
in FIG. 9;
FIG. 11 illustrates a radiation pattern of the antenna shown in FIG. 9;
FIG. 12 shows the structure of a mobile telephone apparatus according to a fourth
embodiment of the present invention;
FIG. 13 illustrates a state in which electric current occurs in the antenna shown
in FIG. 12;
FIG. 14 shows the structure of a mobile telephone apparatus according to a fifth embodiment
of the present invention;
FIG. 15 shows the structure of an antenna included in a mobile telephone apparatus
according to a sixth embodiment of the present invention;
FIG. 16 shows the structure of an antenna included in a mobile telephone apparatus
according to a seventh embodiment of the present invention;
FIG. 17 shows the structure of an antenna included in a mobile telephone apparatus
according to an eighth embodiment of the present invention;
FIG. 18 shows the structure of an antenna included in a mobile telephone apparatus
according to a ninth embodiment of the present invention;
FIG. 19 shows a variation of the antenna included in the mobile telephone apparatus
according to the ninth embodiment of the present invention;
FIGS. 20A and 20B illustrate distributions of current in the antennas shown in FIG.
19 and FIG. 12;
FIG. 21 shows a radiation pattern of the antenna shown in FIG. 19;
FIG. 22 shows a variation in VSWR characteristics due to the presence/absence of short-circuit
elements shown in FIG. 19;
FIG. 23 is a Smith chart indicating a difference in characteristics due to the presence/absence
of the short-circuit elements shown in FIG. 19;
FIG. 24 shows the structure of an antenna included in a mobile telephone apparatus
according to a tenth embodiment of the present invention;
FIG. 25 shows the structure of an antenna included in a mobile telephone apparatus
according to an eleventh embodiment of the present invention;
FIG. 26 shows the structure of a mobile telephone apparatus according to a twelfth
embodiment of the present invention;
FIG. 27 shows the structure of a mobile telephone apparatus according to a 13th embodiment
of the present invention;
FIG. 28 shows the structure of a mobile telephone apparatus according to a 14th embodiment
of the present invention;
FIG. 29 shows the structure of a mobile telephone apparatus according to a 15th embodiment
of the present invention;
FIG. 30 illustrates a variation in VSWR characteristics when the state of the mobile
telephone apparatus is varied, in a case where the mobile telephone apparatus shown
in FIG. 27 is equipped with the antenna shown in FIG. 19;
FIG. 31 illustrates a variation in VSWR characteristics in the open state and closed
state of the casing in the case where the mobile telephone apparatus shown in FIG.
27 is equipped with the antenna shown in FIG. 19;
FIG. 32 shows the structure of a mobile telephone apparatus according to a 16th embodiment
of the present invention;
FIG. 33 illustrates a state in which electric current occurs in the antenna shown
in FIG. 32;
FIG. 34 illustrates a radiation pattern of the antenna shown in FIG. 32;
FIG. 35 illustrates VSWR characteristics of the antenna shown in FIG. 32;
FIG. 36 shows the structure of a mobile telephone apparatus according to a 17th embodiment
of the present invention;
FIG. 37 shows the structure of a mobile telephone apparatus according to a 18th embodiment
of the present invention;
FIG. 38 shows the structure of an antenna included in a mobile telephone apparatus
according to a 19th embodiment of the present invention;
FIG. 39 shows the structure of an antenna included in a mobile telephone apparatus
according to a 20th embodiment of the present invention;
FIG. 40 shows the structure of an antenna included in a mobile telephone apparatus
according to a 21st embodiment of the present invention;
FIG. 41 shows the structure of an antenna included in a mobile telephone apparatus
according to a 22nd embodiment of the present invention;
FIG. 42 shows the structure of an antenna included in a mobile telephone apparatus
according to a 23rd embodiment of the present invention;
FIG. 43 shows the structure of an antenna included in a mobile telephone apparatus
according to a 24th embodiment of the present invention;
FIG. 44 shows the structure of an antenna included in a mobile telephone apparatus
according to a 25th embodiment of the present invention;
FIG. 45 shows the structure of an antenna included in a mobile telephone apparatus
according to a 26th embodiment of the present invention;
FIG. 46 illustrates VSWR characteristics in a case where the antenna shown in FIG.
45 is accommodated in the upper casing shown in FIG. 27;
FIGS. 47A to 47F show radiation patterns of the antenna shown in FIG. 45;
FIG. 48 shows the structure of an antenna included in a mobile telephone apparatus
according to a 27th embodiment of the present invention; and
FIG. 49 shows a variation of the antenna included in the mobile telephone apparatus
according to the 27th embodiment of the present invention.
(First Embodiment)
[0019] A mobile telephone apparatus according to a first embodiment of the present invention
will now be described with reference to FIG. 3 through FIG. 6.
[0020] As is shown in FIG. 3, the mobile telephone apparatus according to the first embodiment
has an antenna 2 built in a casing 1. The antenna 2 includes a dipole antenna 3 and
an opposed element 4. Each of the dipole antenna 3 and opposed element 4 is formed
of a conductor material in a straight shape. The length of the dipole antenna 3 is
equal to a half wavelength. Power feed means 6 feeds power to a substantially middle
point of the dipole antenna 3 in a balanced-feed fashion. Specifically, the dipole
antenna 3, as a single element, functions as a half-wave dipole antenna. The dipole
antenna 3 and opposed element 4 are arranged with a predetermined distance L1. Each
of the dipole antenna 3 and opposed element 4 is disposed in a right-and-left direction.
The distance L1 is 1/4 wavelength (λ/4) or less. The dipole antenna 3 and opposed
element 4 are in line-symmetry with respect to an opposed axis A1. The opposed axis
A1 is parallel to the dipole antenna 3 and opposed element 4 and is located at a middle
point between the dipole antenna 3 and opposed element 4. The dipole antenna 3 and
opposed element 4 are in line-symmetry with respect to a symmetric axis A2. The symmetric
axis A2 intersects the dipole antenna 3 at right angles at a midpoint in the longitudinal
direction of the dipole antenna 3. The dipole antenna 3 and opposed element 4 are
arranged such that an imaginary plane in which the dipole antenna 3 and opposed element
4 are positioned is parallel to the front surface of the casing 1 (the surface on
which the receiver 5 is disposed).
[0021] In FIG. 3, an imaginary plane is shown as being superposed on the front surface of
the casing 1. This is for easy understanding of the relationships between the imaginary
plane and the front surface of the casing 1. It should be noted that the imaginary
plane may be arranged at any position such as a position in front of the casing 1
or a position behind the casing 1. The same is applied to the analogous Figures described
later.
[0022] In the descriptions above and below, the technical terms "opposed axis", "symmetric
axis" and "imaginary plane" are used to explain geometrical concepts and do not designate
physical objects that are structural elements of the mobile wireless communication
terminal.
[0023] If power is supplied from the power feed means 6 to the dipole antenna 3, a drive
current vector V occurs in the dipole antenna 3, as shown in FIG. 4. On the other
hand, an induction current vector Vi, which is induced by the drive current vector
V and has a phase opposite to the phase of the drive current vector V, is caused in
the opposed element 4. The antenna 2 emits radiation by the drive current vector V
and induction current vector Vi.
[0024] When the radiation pattern of the antenna 2 is viewed from the left side of the casing
1, it looks like a simple figure eight, which is substantially symmetric with respect
to the front-and-rear axis, as shown in FIG. 5. The reason for this is that the current
vectors V and Vi have opposite phases and thus the energy radiated from the dipole
antenna 3 and the energy radiated from the opposed element 4 cancel each other in
the vicinity of the center in the front-and-rear direction.
[0025] As is illustrated in FIG. 6, as the distance L1 between the dipole antenna 3 and
opposed element 4 decreases, the ratio between the maximum value and minimum value
of a relative power gain relating to horizontally polarized waves, as viewed from
the left side or right side of the casing 1, becomes higher. In other words, as the
distance L1 between the dipole antenna 3 and opposed element 4 decreases, the electromagnetic
field radiated in the forward or rearward direction of the casing 1 is more suppressed.
On the other hand, as the distance L1 is decreased, the antenna 2 is reduced in size.
[0026] According to the first embodiment, by decreasing the distance L1 between the dipole
antenna 3 and opposed element 4, the electromagnetic field radiated in the forward
direction can be more suppressed and the antenna 2 can be reduced in size. The external
shape of the antenna 2 is thin shape along the front surface of the casing 1. Hence,
in the case where the casing 1 is formed to have a thin shape with an external dimension
in the front-and-rear direction that is less than an external dimension in another
direction, as shown in FIG. 3, the antenna 2 can efficiently be contained within the
casing 1. Therefore, it is possible to obtain a mobile phone apparatus which has a
small size and can decrease degradation in communication performance due to the close
positional relationship between the human body and the front surface of the casing
1. In addition, where the casing 1 is formed to have such a thin shape, a circuit
board, etc. are, in many cases, disposed in parallel to the antenna 2. In such a case,
radiation directed to the circuit board, etc. may considerably be lost due to attenuation
by the circuit board, etc. According to the first embodiment, however, an electromagnetic
field that is radiated toward the rear side where the circuit board, etc. are disposed
is suppressed, and thus the loss due to the circuit board, etc. can be suppressed.
[0027] The opposed element 4 may be inclined relative to the dipole antenna 3. The imaginary
plane in which the dipole antenna 3 and opposed element 4 are positioned may be inclined
relative to the front surface of the casing 1. The dipole antenna 3 and opposed element
4 may not be in line-symmetry with respect to the opposed axis A1. The dipole antenna
3 and opposed element 4 may not be in line-symmetry with respect to the symmetric
axis A2. The length of the dipole antenna 3 may be an odd-number of times of a half
wavelength. It should be noted, however, that as the degree of parallelism or symmetry
becomes lower, the symmetric property of the radiation pattern is degraded. Thus,
in the case where a regular radiation pattern is required, it is desirable to maximize
the degree of parallelism or symmetry.
[0028] Unless the degree of parallelism or symmetry is considerably lowered, the characteristics
of the radiation pattern are maintained. It is also possible to adjust the directivity
by varying the degree of parallelism or symmetry. In general terms, it is preferable
for the use of the mobile telephone apparatus to obtain a relatively high radiation
intensity in the direction of the angle of elevation of the casing 1. The degree of
parallelism or symmetry can be adjusted so as to obtain such a radiation pattern.
[0029] The length of the dipole antenna 3 may be an odd-number of times of a half length.
Theoretically, the optimal length of the dipole antenna 3 is an odd-number of times
of a half length. However, because of the frequency to be used or constraints on mounting,
the optimal length of the dipole antenna 3 is slightly different from an odd-number
of times of a half length.
[0030] The distance L1 between the dipole antenna 3 and opposed element 4 may be made greater
than λ/4.
[0031] The dipole antenna 3 and opposed element 4 may be inclined relative to the lateral
direction.
(Second Embodiment)
[0032] A mobile telephone apparatus according to a second embodiment of the present invention
will now be described with reference to FIG. 7 and FIG. 8. In FIGS. 7 and 8, the structural
elements common to those shown in the preceding Figures are denoted by like reference
numerals, and a detailed description thereof is omitted.
[0033] As is shown in FIG. 7, the mobile telephone apparatus according to the second embodiment
includes an antenna 2 having the same structure as the antenna of the first embodiment.
In the second embodiment, however, the dipole antenna 3 and opposed element 4 are
arranged so as to extend in the up-and-down direction.
[0034] In the second embodiment, the same advantages as with the first embodiment can be
obtained.
[0035] If the "up-and-down" direction in FIG. 3 coincides with the vertical direction, the
dipole antenna 3 and opposed element 4 in the first embodiment are horizontally situated.
Thus, as shown in FIG. 5, the radiation electromagnetic field is mainly composed of
a horizontally polarized wave component, and a vertically polarized wave component
is relatively small. On the other hand, according to the mobile telephone apparatus
of the second embodiment, when the radiation pattern of the antenna 2 is viewed from
the upper side of the casing 1, it looks like a simple figure eight, which is substantially
symmetric with respect to the front-and-rear axis, as shown in FIG. 8. Since the drive
current vector V and induction current vector Vi are substantially vertical, the vertically
polarized wave component can be made greater than the horizontally polarized wave
component.
[0036] The structure of the second embodiment can similarly be modified like the first embodiment.
In the second embodiment, however, if the practicability of the mobile telephone apparatus
is taken into account, it is desirable to maintain the symmetric property of the radiation
pattern.
(Third Embodiment)
[0037] A mobile telephone apparatus according to a third embodiment of the present invention
will now be described with reference to FIG. 9 through FIG. 11. In FIGS. 9 and 10,
the structural elements common to those shown in the preceding Figures are denoted
by like reference numerals, and a detailed description thereof is omitted.
[0038] As is shown in FIG. 9, the mobile telephone apparatus according to the third embodiment
has an antenna 7 built in the casing 1. The antenna 7 includes a dipole antenna 8
and an opposed element 4. In the antenna 7, the dipole antenna 8 is substituted for
the dipole antenna 3 of the antenna 2.
[0039] The dipole antenna 8 is configured such that both end portions of the conductor of
the dipole antenna 3 are bent at right angles. A middle portion of the dipole antenna
8 is referred to as a base portion 8a. The portions bent perpendicular to the base
portion 8a are referred to as bent portions 8b and 8c. The length of the dipole antenna
8 is equal to a half wavelength. The power feed means 6 feeds power to a substantially
middle point of the dipole antenna 8. Specifically, the dipole antenna 8, as a single
element, functions as a half-wave dipole antenna. The dipole antenna 8 and opposed
element 4 are disposed such that the base portion 8a and opposed element 4 have the
same positional relationship as the dipole antenna 3 and opposed element 4 in the
first embodiment. The dipole antenna 8 is disposed such that its bent portions 8b
and 8c are situated away from the opposed element 4. The dipole antenna 8 and opposed
element 4 are arranged such that the imaginary plane in which these elements are positioned
is parallel to the front surface of the casing 1.
[0040] When power is fed to the dipole antenna 8 from the power feed means 6, a drive current
vector Va occurs in the base portion 8a, a drive current vector Vb occurs in the bent
portion 8b and a drive current vector Vc occurs in the bent portion 8c, as shown in
FIG. 10. An induction current vector Vi, which is induced by the drive current vector
Va and has a phase opposite to the phase of the drive current vector Va, is caused
in the opposed element 4.
[0041] The antenna 7 emits electromagnetic field radiation, which is similar with the first
embodiment, by the drive current vector Va and induction current vector Vi. On the
other hand, as shown in FIG. 10, the drive current vectors Vb and Vc occur in the
up-and-down direction and have mutually opposite phases. Accordingly, the functions
of the drive current vectors Vb and Vc are substantially equivalent to those of the
drive current vectors V and Vi in the second embodiment. The radiation pattern of
the antenna 7, when viewed from the upper side of the casing 1, it looks like a simple
figure eight, which is substantially symmetric with respect to the front-and-rear
axis, as shown in FIG. 11. If the "up-and-down" direction in FIG. 9 is the vertical
direction, the drive current vectors Vb and Vc are substantially vertical, so the
vertically polarized wave component becomes greater than the horizontally polarized
wave component.
[0042] Therefore, in the third embodiment, the same advantages as with the first embodiment
can be obtained. According to the third embodiment, the horizontally polarized wave
component is mainly radiated by the functions of the drive current vector Va and induction
current vector Vi, and the vertically polarized wave component is mainly radiated
by the functions of the drive current vectors Vb and Vc. Hence, both polarized wave
components can sufficiently be radiated. Which of the horizontally and vertically
polarized wave components is dominant is determined by the ratio in length between
the base portion 8a and the bent portion 8b, 8c of the dipole antenna 8.
[0043] The structure of the third embodiment may be modified as in the first embodiment.
(Fourth Embodiment)
[0044] A mobile telephone apparatus according to a fourth embodiment of the present invention
will now be described with reference to FIG. 12 and FIG. 13. In FIGS. 12 and 13, the
structural elements common to those shown in the preceding Figures are denoted by
like reference numerals, and a detailed description thereof is omitted.
[0045] As is shown in FIG. 12, the mobile telephone apparatus according to the fourth embodiment
has an antenna 9 accommodated in the casing 1. The antenna 9 includes a dipole antenna
8 and an opposed element 10. In the antenna 9, the opposed element 10 is substituted
for the opposed element 4 of the antenna 7.
[0046] The opposed element 10 is configured such that both end portions of the conductor
of the opposed element 4 are bent at right angles. A middle portion of the opposed
element 10 is referred to as a base portion 10a. The portions bent perpendicular to
the base portion 10a are referred to as bent portions 10b and 10c. The dipole antenna
8 and opposed element 10 are disposed such that the base portion 8a and the base portion
10a have the same positional relationship as the dipole antenna 3 and opposed element
4 in the first embodiment. The dipole antenna 8 and opposed element 10 are disposed
such that the bent portions 8b and 8c and the bent portions 10b and 10c are situated
away from each other. The dipole antenna 8 and opposed element 10 are arranged such
that the imaginary plane in which these elements are positioned is parallel to the
front surface of the casing 1.
[0047] When power is fed to the dipole antenna 8 from the power feed means 6, a drive current
vector Va occurs in the base portion 8a, a drive current vector Vb occurs in the bent
portion 8b and a drive current vector Vc occurs in the bent portion 8c, as shown in
FIG. 13. An induction current vector Via, which is induced by the drive current vector
Va and has a phase opposite to the phase of the drive current vector Va, is caused
in the base portion 10a of the opposed element 10. With the occurrence of the induction
current vector Via, an induction current vector Vib occurs in the bent portion 10b
and an induction current vector Vic occurs in the bent portion 10c.
[0048] The antenna 9 emits electromagnetic field radiation, which is similar with the first
embodiment, by the functions of the drive current vector Va and induction current
vector Via. On the other hand, as shown in FIG. 11, the drive current vectors Vb and
Vc and induction current vectors Vib and Vic occur in the up-and-down direction. The
drive current vector Vb and induction current vector Vib have the same direction,
and the drive current vector Vc and induction current vector Vic have the same direction.
The drive current vector Vb and induction current vector Vib have opposite phases,
and the drive current vector Vc and induction current vector Vic have opposite phases.
Accordingly, by the functions of the drive current vector Vb and induction current
vector Vib and the drive current vector Vc and induction current vector Vic, the radiation
pattern of the antenna 9, when viewed from the upper side of the casing 1, it looks
like a simple figure eight, which is substantially symmetric with respect to the front-and-rear
axis. If the "up-and-down" direction in FIG. 12 is the vertical direction, the drive
current vectors Vb and Vc and the induction current vectors Vib and Vic are substantially
vertical, so the vertically polarized wave component becomes greater than the horizontally
polarized wave component.
[0049] Therefore, in the fourth embodiment, the same advantages as with the first embodiment
can be obtained. According to the fourth embodiment, the horizontally polarized wave
component is mainly radiated by the functions of the drive current vector Va and induction
current vector Via, and the vertically polarized wave component is mainly radiated
by the functions of the drive current vectors Vb and Vc and the induction current
vectors Vib and Vic. Hence, both polarized wave components can sufficiently be radiated.
[0050] The structure of the fourth embodiment can also be modified like the first embodiment.
(Fifth Embodiment)
[0051] A mobile telephone apparatus according to a fifth embodiment of the present invention
will now be described with reference to FIG. 14. In FIG. 14, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0052] As is shown in FIG. 7, the mobile telephone apparatus according to the fifth embodiment
has an antenna 9 having the same structure as the antenna 9 of the first embodiment.
In the fifth embodiment, however, the base portions 8a and 10a are disposed in the
up-and-down direction.
[0053] Thus, in the fifth embodiment, the same advantages as with the first embodiment can
be obtained. According to the fifth embodiment, the vertically polarized wave component
is mainly radiated by the functions of the drive current vector Va and induction current
vector Vi, and the horizontally polarized wave component is mainly radiated by the
functions of the drive current vectors Vb and Vc and the induction current vectors
Vib and Vic. Hence, both polarized wave components can sufficiently be radiated.
[0054] The structure of the fifth embodiment can also be modified like the first embodiment.
It is desirable, however, that the base portions 8a and 10a be disposed in line-symmetry
with respect to the opposed axis A1 in order to maintain the symmetric property of
the vertically polarized wave component in the left-and-right axial direction.
(Sixth Embodiment)
[0055] A mobile telephone apparatus according to a sixth embodiment of the present invention
will now be described with reference to FIG. 15. In FIG. 15, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 15 shows only the structure of
an antenna 11 built in the mobile telephone apparatus according to the sixth embodiment.
[0056] The mobile telephone apparatus according to the sixth embodiment is based on the
mobile telephone apparatus according to the fourth embodiment, and it includes the
antenna 11 which is obtained by modifying the antenna 9. The antenna 11 includes a
dipole antenna 12 and the opposed element 10. Specifically, the antenna 11 includes
the dipole antenna 12 in place of the dipole antenna 8 of the antenna 9.
[0057] The dipole antenna 12, like the dipole antenna 8, is formed of a conductor material
so as to have a base portion 12a and bent portions 12b and 12c. The bent portions
12b and 12c, however, are opened outward, while being line-symmetric with respect
to the symmetric axis A2.
[0058] Even with this configuration, the radiation pattern mainly comprising the vertically
polarized wave component can be kept symmetric with respect to the front-and-rear
axis. On the other hand, the dipole antenna 12 and opposed element 10 are not in line-symmetry
with respect to the opposed axis A1. Consequently, the radiation pattern mainly comprising
the horizontally polarized wave component is not symmetric with respect to the up-and-down
axial direction. It should be noted, however, that the feature that there is no radiation
directivity toward the front or the rear remains unchanged. As a result, the same
advantages as with the first embodiment can be obtained.
[0059] Moreover, the radiation directivity of the horizontally polarized wave component
in the up-and-down axial direction can be optimized by properly determining the angle
of the bent portion 12b, 12c.
[0060] The structure of the sixth embodiment may be modified as in the first embodiment.
(Seventh Embodiment)
[0061] A mobile telephone apparatus according to a seventh embodiment of the present invention
will now be described with reference to FIG. 16. In FIG. 16, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 16 shows only the structure of
an antenna 13 built in the mobile telephone apparatus according to the seventh embodiment.
[0062] The mobile telephone apparatus according to the seventh embodiment is based on the
mobile telephone apparatus according to the fourth embodiment, and it includes the
antenna 13 which is obtained by modifying the antenna 9. The antenna 11 includes a
dipole antenna 14 and an opposed element 15.
[0063] The dipole antenna 14, like the dipole antenna 8, is formed of a conductor material
so as to have a base portion 14a and bent portions 14b and 14c. The base portion 14a,
however, has such a bent shape that the base portion 14a gradually approaches the
opposed element 15 from its middle point toward its both ends. The base portion 14a
is line-symmetric with respect to the symmetric axis A2. The bent portions 14b and
14c are opened outward, while being line-symmetric with respect to the symmetric axis
A2.
[0064] The opposed element 15, like the opposed element 10, is formed so as to have a base
portion 15a and bent portions 15b and 15c. The base portion 15a, however, has such
a bent shape that the base portion 15a gradually approaches the dipole antenna 14
from its middle point toward its both ends. The base portion 14a and base portion
15a are line-symmetric with respect to the opposed axis A1.
[0065] With this configuration, the same advantages as with the sixth embodiment can be
obtained by the same functions as with the sixth embodiment.
[0066] The structure of the seventh embodiment may be modified as in the first embodiment.
(Eighth Embodiment)
[0067] A mobile telephone apparatus according to an eighth embodiment of the present invention
will now be described with reference to FIG. 17. In FIG. 17, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 17 shows only the structure of
an antenna 16 that is built in the mobile telephone apparatus according to the eighth
embodiment.
[0068] The mobile telephone apparatus according to the eighth embodiment is based on the
mobile telephone apparatus according to the fourth embodiment, and it includes the
antenna 16 which is obtained by modifying the antenna 9. The antenna 16 includes a
dipole antenna 17 and an opposed element 18.
[0069] The dipole antenna 17 is formed by adding a shorting element 17a of a conductor material
to the dipole antenna 8. The shorting element 17a short-circuits the bent portions
8b and 8c.
[0070] The opposed element 18 is formed by adding a shorting element 18a of a conductor
material to the opposed element 10. The shorting element 18a short-circuits the bent
portions 10b and 10c.
[0071] The antenna 16 has an impedance that varies depending on the distance between the
base portion 8a and shorting element 17a and the distance between the base portion
10a and shorting element 18a. By properly determining these distances, impedance matching
can be effected between the power feed means 6 and antenna 16.
[0072] The structure of the eighth embodiment may be modified as in the first embodiment.
(Ninth Embodiment)
[0073] A mobile telephone apparatus according to a ninth embodiment of the present invention
will now be described with reference to FIG. 18 through FIG. 23. In FIGS. 18 and 19,
the structural elements common to those shown in the preceding Figures are denoted
by like reference numerals, and a detailed description thereof is omitted. FIG. 18
and FIG. 19 show only the structure of an antenna 19, 22 built in the mobile telephone
apparatus according to the ninth embodiment.
[0074] The mobile telephone apparatus according to the ninth embodiment is based on the
mobile telephone apparatus according to the fourth embodiment, and it includes the
antenna 19 which is obtained by modifying the antenna 9. The antenna 19 is formed
by adding shorting elements 20 and 21 of conductor material to the antenna 9. The
shorting elements 20 and 21 short-circuit the dipole antenna 8 and opposed element
10.
[0075] The antenna 22 shown in FIG. 19 is a variation of the antenna 19. The antenna 22
includes shorting elements 23 and 24 formed of conductor material in the same shape
as the dipole antenna 8 and opposed element 10. The shorting element 23 short-circuits
the bent portions 8b and 10b, and the shorting element 24 short-circuits the bent
portions 8c and 10c. In FIG. 19, reference numeral 25 denotes a board accommodated
in the casing 1 along with the antenna 22.
[0076] The antenna 22 has a current distribution as shown in FIG. 20A. On the other hand,
the antenna 9 has a current distribution as shown in FIG. 20B. The degrees of current
balance in FIGS. 20A and 20B are 95% and 81%, respectively. That is, the current distribution
in the antenna 22 has a higher degree of current balance than the current distribution
in the antenna 9. Thus, as shown in FIG. 21, a null appears clearly in the radiation
pattern of the antenna 22, as viewed from the upper side of the casing 1. In FIG.
21, the forward direction corresponds to the direction of 0 degree (i.e. the right-hand
direction of the horizontal axis). According to the radiation pattern shown in FIG.
21, it is understood that a null of the vertically polarized wave component indicated
by the solid line is formed in good condition in the forward direction.
[0077] On the other hand, as shown in FIGS. 22 and 23, the addition of the shorting elements
23 and 24 increases the impedance. Thus, even if the PCB-GND provided at the board
25 is situated close to the antenna 22, the impedance matching can be achieved.
[0078] The shape of the shorting elements and the locations of connection of the shorting
elements to the dipole antenna 8 and opposed element 10 can freely be chosen. It is
desirable, however, to maintain the symmetry with respect to the symmetric axis A2.
[0079] The structure of the ninth embodiment may be modified as in the first embodiment.
(Tenth Embodiment)
[0080] A mobile telephone apparatus according to a tenth embodiment of the present invention
will now be described with reference to FIG. 24. In FIG. 24, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0081] The mobile telephone apparatus according to the tenth embodiment is based on the
mobile telephone apparatus according to the fourth embodiment. In the tenth embodiment,
the mode of power feed is altered. Specifically, power feed means 26 is added. The
power feed means 26 feeds power to the opposed element 10 with a phase that is opposite
to the phase of the power feed means 6.
[0082] With this structure, an induction current vector induced by the dipole antenna 8
and a drive current vector fed from the power feed means 26 are added in the reverse
phase in the opposed element 10. Therefore, the same advantages as with the fourth
embodiment can be obtained, and the radiation intensity can be increased.
[0083] This mode of power feed is also applicable to a configuration that is based on embodiments
other than the fourth embodiment of the present invention.
(Eleventh Embodiment)
[0084] A mobile telephone apparatus according to an eleventh embodiment of the present invention
will now be described with reference to FIG. 25. In FIG. 25, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0085] The mobile telephone apparatus according to the eleventh embodiment is based on the
mobile telephone apparatus according to the fourth embodiment. In the eleventh embodiment,
the mode of power feed is altered. Specifically, the position of the power feed means
6 is displaced from the middle point of the base portion 8a.
[0086] With this structure, too, the drive current vector Vb in the bent portion 8b and
the drive current vector Vc in the bent portion 8c can maintain the relationship of
opposite phases, as far as the dipole antenna 8 is configured to have a proper length
based on an odd-number of times of λ/2. Therefore, the same advantages as with the
fourth embodiment can be achieved.
[0087] This mode of power feed is also applicable to a configuration that is based on embodiments
other than the fourth embodiment of the present invention.
[0088] The structure of the eleventh embodiment may be modified as in the first embodiment.
(Twelfth Embodiment)
[0089] A mobile telephone apparatus according to a twelfth embodiment of the present invention
will now be described with reference to FIG. 26. In FIG. 26, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0090] The mobile telephone apparatus according to the twelfth embodiment is based on the
mobile telephone apparatus according to the fourth embodiment, and it includes the
antenna 27 which is obtained by modifying the antenna 9. The antenna 27 includes a
dipole antenna 28 and the opposed element 10. Specifically, the antenna 27 includes
the dipole antenna 28 in place of the dipole antenna 8 of the antenna 9.
[0091] The dipole antenna 28 is formed as a conductor pattern on a board 29 that is built
in the casing 1. The dipole antenna 28 includes a base portion 28a and bent portions
28b and 28c. The shape and the position of the dipole antenna 28 are the same as those
of the dipole antenna 8.
[0092] With this structure, when the board 29 is fabricated, the dipole antenna 28 can be
formed at the same time. If the board 29 is mounted in the casing 1, the dipole antenna
28 can also be mounted. In addition, if the opposed element 10 is disposed in the
casing 1, the antenna 27 can be formed. Thus, the mobile telephone apparatus according
to the twelfth embodiment can efficiently be manufactured.
[0093] This mode of mounting is also applicable to a configuration that is based on embodiments
other than the fourth embodiment of the present invention.
[0094] The structure of the twelfth embodiment may be modified as in the first embodiment.
(13th Embodiment)
[0095] A mobile telephone apparatus according to a 13th embodiment of the present invention
will now be described with reference to FIG. 27. In FIG. 27, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0096] The mobile telephone apparatus according to the 13th embodiment includes an upper
casing 30 and a lower casing 31 that are configured to be foldable by means of a hinge
(not shown). Electric circuits accommodated in the upper casing 30 and lower casing
31 are electrically connected by means of a connection member 32 such as a flexible
board.
[0097] The upper casing 30 contains the antenna 9. The antenna 9 is configured such that
the imaginary plane in which the dipole antenna 8 and opposed element 10 are positioned
is parallel to the front surface of the upper casing 30.
[0098] With the structure of the 13th embodiment, the same advantages as with the fourth
embodiment can be obtained.
[0099] This mode of mounting is also applicable to a configuration that is based on embodiments
other than the fourth embodiment of the present invention.
[0100] The structure of the 13th embodiment may be modified as in the first embodiment.
(14th Embodiment)
[0101] A mobile telephone apparatus according to a 14th embodiment of the present invention
will now be described with reference to FIG. 28. In FIG. 28, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0102] The mobile telephone apparatus according to the 14th embodiment includes an upper
casing 30 and a lower casing 31, like the 13th embodiment. The dipole antenna 8 is
accommodated in the lower casing 31 such that the imaginary plane in which the base
element 8a and bent elements 8b and 8c are positioned is parallel to the front surface
of the lower casing 31. The opposed element 10 is accommodated in the upper casing
30 such that the imaginary plane in which the base element 10a and bent elements 10b
and 10c are positioned is parallel to the front surface of the upper casing 30.
[0103] With the structure of the 14th embodiment, the same advantages as with the fourth
embodiment can be obtained.
[0104] This mode of mounting is also applicable to the case of using antennas according
to embodiments other than the fourth embodiment of the present invention.
[0105] The structure of the 14th embodiment may be modified as in the first embodiment.
(15th Embodiment)
[0106] A mobile telephone apparatus according to a 15th embodiment of the present invention
will now be described with reference to FIG. 29. In FIG. 29, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0107] The mobile telephone apparatus according to the 15th embodiment includes the upper
casing 30 and lower casing 31, like the 13th embodiment. Electric circuits accommodated
in the upper casing 30 and lower casing 31 are electrically connected by means of
a connection member 33 such as a flexible board.
[0108] The mobile telephone apparatus according to the 15th embodiment includes an antenna
34 that is formed by modifying the antenna 9 of the fourth embodiment. The antenna
34 includes the dipole antenna 8 and an opposed element 35. Specifically, the antenna
34 includes the opposed element 35 that is substituted for the opposed element 10
of the antenna 9.
[0109] The opposed element 35 is formed as a conductor pattern on the connection member
33. The opposed element 35 includes a base portion 35a and bent portions 35b and 35c.
The opposed element 35 has the same shape as the opposed element 10. The imaginary
plane in which the base portion 35a and bent portions 35b and 35c of the opposed element
35 are positioned is parallel to the front surface of the upper casing 30 in the state
in which the upper casing 30 and lower casing 31 are opened, as shown in FIG. 29.
[0110] With the structure of the 15th embodiment, the same advantages as with the fourth
embodiment can be obtained. In addition, according to the 15th embodiment, it should
suffice if only the dipole antenna 8 is accommodated in the casing. Thus, the size
of the casing can further be reduced.
[0111] The structure of the 15th embodiment may be modified as in the first embodiment.
[0112] Besides, in the 15th embodiment, the dipole antenna 8 may be accommodated in the
upper casing 30. It is possible that the dipole antenna is formed of a conductor pattern
on the connection member and the opposed element 35 is accommodated in the upper casing
30 or lower casing 31. Both the dipole antenna and opposed element may be formed of
conductor patterns on the connection member.
[0113] The antenna in each of the first to 15th embodiments is basically composed of a balanced-type
dipole antenna, and an opposed element is additionally provided. Thus, a current decreases,
which flows, according to radiation from the antenna, on the board accommodated in
the casing along with the antenna. As a result, a variation in voltage standing-wave
ratio (VSWR), which depends on the change of the condition of use, decreases. In short,
such an advantage can be obtained that the variation in input impedance due to the
change of the state of use is small and an increase of mismatching loss will hardly
occur.
[0114] Assume that the antenna 9 of the mobile wireless communication terminal shown in
FIG. 27 is replaced with the antenna 22 shown in FIG. 19. FIG. 30 and FIG. 31 show
experimental values of VSWR relating to this mobile wireless communication terminal.
[0115] As is understood from FIG. 30, the VSWR characteristics do not greatly vary between
the following states: a state (Free) in which the mobile wireless communication terminal
is disposed in a free space, a state (Hand) in which the lower casing 31 is held by
the hand, and a state (Head) in which the lower casing 31 is held by the hand and
the upper casing 30 is positioned close to the head. As is understood from FIG. 31,
the VSWR characteristics do not greatly vary between the following states: a state
(OPEN) in which the upper casing 30 and lower casing 31 are opened and a state (CLOSE)
in which the upper casing 30 and lower casing 31 are closed.
(16th Embodiment)
[0116] A mobile telephone apparatus according to a 16th embodiment of the present invention
will now be described with reference to FIG. 32 through FIG. 35. In FIG. 32 and FIG.
33, the structural elements common to those shown in the preceding Figures are denoted
by like reference numerals, and a detailed description thereof is omitted.
[0117] As is shown in FIG. 32, the mobile telephone apparatus according to the 16th embodiment
includes an antenna 36 built in the casing 1. The antenna 36 includes the dipole antenna
3, the opposed element 4, and parasitic elements 37 and 38. Specifically, the antenna
36 is formed by adding parasitic elements 37 and 38 to the antenna 2 of the first
embodiment.
[0118] The parasitic elements 37 and 38 are formed of conductor material in a straight shape.
The length of each parasitic element 37, 38 differs from that of the dipole antenna
3. In FIG. 32, each parasitic element 37, 38 is shorter than the dipole antenna 3.
The parasitic elements 37 and 38 are disposed in the imaginary plane in which the
dipole antenna 3 and opposed element 4 are positioned. The parasitic element 37 is
spaced apart from the dipole antenna 3 by a predetermined distance L2 and is parallel
to the dipole antenna 3. The parasitic element 38 is spaced apart from the opposed
element 4 by a predetermined distance L3 and is parallel to the opposed element 4.
The distance L2, L3 is λ/4 or less. In other words, the parasitic element 38, opposed
element 4, dipole antenna 3 and parasitic element 37 are arranged in the named order
in the up-and-down direction of the casing 1 at intervals of λ/4 or less. The parasitic
elements 37 and 38 are configured to be in line-symmetry with respect to the symmetric
axis A2.
[0119] When power is fed from the power feed means 6 to the dipole antenna 3, a drive current
vector V occurs in the dipole antenna 3, as shown in FIG. 33. An induction current
vector Vi1, which is induced by the drive current vector V and has a phase opposite
to the phase of the drive current vector V, is caused in the opposed element 4. An
induction current vector Vi2, which is induced by the drive current vector V and has
a phase opposite to the phase of the drive current vector V, is caused in the parasitic
element 37. An induction current vector Vi3, which is induced by the induction current
vector Vi1 and has the same phase as the drive current vector V, is caused in the
parasitic element 38. The antenna 36 emits radiation by the drive current vector V
and induction current vectors Vi1, Vi2 and Vi3.
[0120] When the radiation pattern of the antenna 36 is viewed from the left side of the
casing 1, it looks like a simple figure eight, which is substantially symmetric with
respect to the front-and-rear axis, as shown in FIG. 34. The reason for this is that
the current vectors v and Vi1 have opposite phases and thus the energy radiated from
the dipole antenna 3 and the energy radiated from the opposed element 4 cancel each
other in the vicinity of the center in the front-and-rear direction. Since the dipole
antenna 3 and opposed element 4 are disposed in the right-and-left direction of the
casing 1, the horizontally polarized wave component is dominant, relative to the vertically
polarized wave component. Since the dipole antenna 3 and opposed element 4 are configured
to be in line-symmetry with respect to the symmetric axis A2, the radiation pattern
(not shown) as viewed from the front side of the casing 1 is symmetric in the right-and-left
direction.
[0121] A VSWR with reference to the power feed means 6, which relates to only the functions
of the dipole antenna 3 and opposed element 4, has characteristics as shown by a broken
line in FIG. 35. In short, single-peak frequency characteristics with a first resonance
point are obtained. The frequency at the first resonance point is determined by the
length of the dipole antenna 3.
[0122] On the other hand, since the induction current vectors V12 and V13 have opposite
phases, the radiation pattern formed by these vectors has the same shape as shown
in FIG. 34. A VSWR, which relates to only the functions of the parasitic elements
37 and 38, also has single-peak frequency characteristics. However, since the parasitic
element 37, 38 has a length different from the length of the dipole antenna 6, a second
resonance point with a frequency different from the frequency of the first resonance
point occurs depending on the functions of the parasitic elements 37 and 38. If the
parasitic element 37, 38 is shorter than the dipole antenna 6, as shown in FIG. 32,
the second resonance point has a higher frequency than the first resonance point.
The VSWR of the antenna 36 has frequency characteristics that are obtained by compounding
these two characteristics. That is, double-peak frequency characteristics are obtained
as shown by a solid line in FIG. 35.
[0123] One of the resonance points in the frequency characteristics shown by the solid line
in FIG. 35 is obtained from the first resonance point, but these points do not coincide,
as shown in FIG. 35, because of the effect of the functions of the parasitic elements
37 and 38. Note that for the purpose of easier understanding, FIG. 35 shows the displacement
in a larger scale than the actual one.
[0124] As is understood from FIG. 35, the antenna 36 has a broader frequency band than the
antenna 2 of the first embodiment which comprises only the dipole antenna 3 and opposed
element 4.
[0125] In the 16th embodiment, the addition of the parasitic elements 37 and 38 makes the
size of the antenna 36 larger than the antenna 2. However, since the parasitic elements
37 and 38 are disposed in the same imaginary plane as the dipole antenna 3 and opposed
element 4, the antenna 36, like the antenna 2, has a thin external shape along the
front surface of the casing 1. Hence, when the casing 1 is formed to have a thin shape
with a small thickness in the front-and-rear direction, the antenna 36 can efficiently
be accommodated in the casing 1. Therefore, it is possible to obtain a mobile telephone
apparatus which has a small size and can decrease degradation in communication performance
due to the close positional relationship between the human body and the front surface
of the casing 1.
[0126] The structure of the 16th embodiment may be modified as in the first embodiment.
In the 16th embodiment, the parasitic elements 37 and 38 may be inclined relative
to the dipole antenna 3 and opposed element 4. The parasitic elements 37 and 38 may
not be in line-symmetry with respect to the symmetric axis A2. It should be noted,
however, that as the degree of parallelism or symmetry becomes lower, the symmetric
property of the radiation pattern is degraded. Thus, in the case where a regular radiation
pattern is required, it is desirable to maximize the degree of parallelism or symmetry.
[0127] The parasitic element 37, 38 may be longer than the dipole antenna 3. In this case,
the second resonance point has a lower frequency than the first resonance point.
[0128] The distance L2, L3 may be greater than λ/4.
[0129] The direction of the dipole antenna 3 and opposed element 4 may be inclined relative
to the right-and-left direction.
[0130] The antenna 36 may be contained in the upper casing 30 or the lower casing 31.
(17th Embodiment)
[0131] A mobile telephone apparatus according to a 17th embodiment of the present invention
will now be described with reference to FIG. 36. In FIG. 36, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0132] As is shown in FIG. 36, the mobile telephone apparatus according to the 17th embodiment
includes an antenna 39 that is built in the casing 1. The antenna 39 includes the
dipole antenna 8, opposed element 10, and parasitic elements 37 and 38. Specifically,
the antenna 39 is formed by adding parasitic elements 37 and 38 to the antenna 9 of
the fourth embodiment.
[0133] The parasitic element 37, 38 is shorter than the base portion 8a. The parasitic element
37 is disposed such that the relationship between the base portion 8a and parasitic
element 37 coincides with the relationship between the dipole antenna 3 and parasitic
element 37 in the 16th embodiment. The parasitic element 38 is disposed such that
the relationship between the base portion 10a and parasitic element 38 coincides with
the relationship between the opposed element 10 and parasitic element 38 in the 16th
embodiment.
[0134] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
39 emits radiation, similarly with the fourth embodiment, by the functions of the
drive current vector occurring in the dipole antenna 8 and the induction current vector
occurring in the opposed element 10. On the other hand, the antenna 39 emits radiation,
similarly with the 16th embodiment, by the functions of the induction current vectors
occurring in the parasitic elements 37 and 38. In addition, since the parasitic element
37, 38 is shorter than the dipole antenna 8, the VSWR of the antenna 39 has double-peak
frequency characteristics for the same reason as has been stated in connection with
the 16th embodiment.
[0135] Thus, with the 17th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 17th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0136] The structure of the 17th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0137] The antenna 39 may be contained in the upper casing 30 or the lower casing 31.
(18th Embodiment)
[0138] A mobile telephone apparatus according to an 18th embodiment of the present invention
will now be described with reference to FIG. 37. In FIG. 37, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted.
[0139] As is shown in FIG. 37, the mobile telephone apparatus according to the 18th embodiment
includes an antenna 40 that is built in the casing 1. The antenna 40 includes the
dipole antenna 8, opposed element 10, and parasitic elements 37 and 38. Specifically,
the antenna 40 is formed by adding parasitic elements 37 and 38 to the antenna 9 of
the fourth embodiment.
[0140] The parasitic element 37, 38 is shorter than the dipole antenna 8. The parasitic
elements 37 and 38 are arranged to sandwich the dipole antenna 8 and opposed element
10. The parasitic element 37 is disposed in parallel to the bent portions 8b and 10b.
The parasitic element 38 is disposed in parallel to the bent portions 8c and 10c.
The parasitic elements 37 and 38 are disposed in the imaginary plane in which the
dipole antenna 8 and opposed element 10 are positioned.
[0141] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
40 emits radiation, similarly with the fourth embodiment, by the functions of the
drive current vector occurring in the dipole antenna 8 and the induction current vector
occurring in the opposed element 10. On the other hand, the antenna 40 emits radiation,
similarly with the 16th embodiment, by the functions of the induction current vectors
occurring in the parasitic elements 37 and 38. In addition, since the parasitic element
37, 38 is shorter than the dipole antenna 8, the VSWR of the antenna 40 has double-peak
frequency characteristics for the same reason as has been stated in connection with
the 16th embodiment.
[0142] In the 18th embodiment, however, the direction of the parasitic elements 37 and 38
is rotated by 90° relative to the direction of the parasitic elements 37 and 38 in
the 16th or 17th embodiment. That is, the parasitic elements 37 and 38 are disposed
in the up-and-down direction. Thus, the second resonance point appears conspicuously
in the vertically polarized wave component in the 18th embodiment, while it appears
conspicuously in the horizontally polarized wave component in the 16th or 17th embodiment.
[0143] Thus, with the 18th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 18th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0144] The structure of the 18th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0145] The antenna 40 may be contained in the upper casing 30 or the lower casing 31.
(19th Embodiment)
[0146] A mobile telephone apparatus according to a 19th embodiment of the present invention
will now be described with reference to FIG. 38. In FIG. 38, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 38 shows only the structure of
an antenna 41 built in the mobile telephone apparatus according to the 19th embodiment.
[0147] The mobile telephone apparatus according to the 19th embodiment is based on the mobile
telephone apparatus according to the fourth embodiment, and it includes the antenna
41 which is obtained by modifying the antenna 9. The antenna 41 includes the dipole
antenna 8, opposed element 10, and parasitic elements 42 and 43. Specifically, the
antenna 41 is formed by adding the parasitic elements 42 and 43 to the antenna 9.
[0148] The parasitic element 42, like the dipole antenna 8, is formed of a conductor material
so as to have a base portion 42a and bent portions 42b and 42c. The base portion 42a
and bent portions 42b and 42c are shorter than the base portion 8a and bent portions
8b and 8c, respectively. The parasitic element 42 is disposed inside the dipole antenna
8 such that the base portion 42a and bent portions 42b and 42c are parallel to the
base portion 8a and bent portions 8b and 8c, respectively.
[0149] The parasitic element 43, like the opposed element 10, is formed of a conductor material
so as to have a base portion 43a and bent portions 43b and 43c. The base portion 43a
and bent portions 43b and 43c are shorter than the base portion 10a and bent portions
10b and 10c, respectively. The parasitic element 43 is disposed inside the opposed
element 10 such that the base portion 43a and bent portions 43b and 43c are situated
parallel to the base portion 10a and bent portions 10b and 10c, respectively.
[0150] The parasitic elements 42 and 43 are disposed in the imaginary plane in which the
dipole antenna 8 and opposed element 10 are positioned. The parasitic elements 42
and 43 are in line-symmetry with respect to the symmetric axis A2.
[0151] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
41 emits radiation, similarly with the fourth embodiment, by the functions of the
drive current vector occurring in the dipole antenna 8 and the induction current vector
occurring in the opposed element 10. On the other hand, since the induction current
vectors occurring in the parasitic elements 42 and 43 have opposite phases, the antenna
41 emits radiation by functions similar to the functions of the drive current vector
occurring in the dipole antenna 8 and the induction current vector occurring in the
opposed element 10. In addition, since the parasitic element 42, 43 is shorter than
the dipole antenna 8, the VSWR of the antenna 41 has double-peak frequency characteristics
for the same reason as has been stated in connection with the 16th embodiment.
[0152] In the 19th embodiment, the base portion 42a of parasitic element 42 is perpendicular
to the bent portions 42b and 42c, and the base portion 43a of parasitic element 43
is perpendicular to the bent portions 43b and 43c. Thus, the second resonance point
appears conspicuously in each of the vertically polarized wave component and horizontally
polarized wave component.
[0153] Thus, with the 19th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 19th embodiment, the vertically polarized
wave component can fully be radiated, and a broad frequency band is realized.
[0154] The structure of the 19th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0155] The antenna 41 may be contained in the upper casing 30 or the lower casing 31.
(20th Embodiment)
[0156] A mobile telephone apparatus according to a 20th embodiment of the present invention
will now be described with reference to FIG. 39. In FIG. 39, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 39 shows only the structure of
an antenna 44 that is built in the mobile telephone apparatus according to the 20th
embodiment.
[0157] As is shown in FIG. 39, the mobile telephone apparatus according to the 20th embodiment
includes the antenna 44 built in the casing 1. The antenna 44 includes the dipole
antenna 8, opposed element 10, and parasitic elements 37 and 38.
[0158] Specifically, the antenna 44 includes the same elements as those of the antenna 39
of the 17th embodiment. The parasitic elements 37 and 38 are disposed along the base
portions 8a and 10a in an imaginary plane that is different from the imaginary plane
in which the dipole antenna 8 and opposed element 10 are positioned. Each of the parasitic
elements 37 and 38 is line-symmetric with respect to a symmetric axis A3. The symmetric
axis A3 is parallel to the symmetric axis A2 with a distance of λ/4 or less in the
forward direction. In the description below, the imaginary planes in which the symmetric
axes A2 and A3 are positioned are referred to as a first imaginary plane and a second
imaginary plane, respectively.
[0159] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
44 emits radiation similarly with the 17th embodiment.
[0160] In the 20th embodiment, the dipole antenna 8 and opposed element 10 are disposed
in the first imaginary plane, and the parasitic elements 37 and 38 are disposed in
the second imaginary plane, the first and second imaginary planes being arranged in
the front-and-rear direction. Consequently, the thickness of the antenna 44 in the
front-and-rear direction becomes larger than that of the antenna 39 of the 17th embodiment.
However, since the distance between the first and second imaginary planes can be set
at λ/4 or less, the thickness of the casing 1 in the front-and-rear direction is not
greatly increased. Conversely, since the inside areas of the dipole antenna 8 and
opposed element 10 can effectively be used for disposing other components, the thickness
of the casing 1 may possibly be reduced by devising arrangement of other components.
[0161] Thus, with the 20th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 20th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0162] The structure of the 20th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0163] In the 20th embodiment, the first imaginary plane and the second imaginary plane
may be reversely positioned in the front-and-rear direction.
[0164] Besides, in the 20th embodiment, the second imaginary plane may be inclined relative
to the first imaginary plane. It should be noted, however, that as the degree of parallelism
between the first and second imaginary planes becomes lower, the symmetric property
of the radiation pattern is degraded. Thus, in the case where a regular radiation
pattern is required, it is desirable to maximize the degree of parallelism between
the first and second imaginary planes.
[0165] The antenna 44 may be contained in the upper casing 30 or the lower casing 31.
(21st Embodiment)
[0166] A mobile telephone apparatus according to a 21st embodiment of the present invention
will now be described with reference to FIG. 40. In FIG. 40, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 40 shows only the structure of
an antenna 45 that is built in the mobile telephone apparatus according to the 21st
embodiment.
[0167] As is shown in FIG. 40, the mobile telephone apparatus according to the 21st embodiment
includes the antenna 45 built in the casing 1. The antenna 45 includes the dipole
antenna 8, opposed element 10, and parasitic elements 37 and 38.
[0168] Specifically, the antenna 45 includes the same elements as those of the antenna 40
of the 18th embodiment. The parasitic elements 37 and 38 are disposed along the bent
portions 8b and 10b and the bent portions 8c and 10c, respectively. The parasitic
elements 37 and 38 are line-symmetric with respect to the symmetric axis A3.
[0169] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
45 emits radiation similarly with the 18th embodiment.
[0170] In the 21st embodiment, the thickness of the antenna 45 in the front-and-rear direction
and the thickness of the casing 1 in the front-and-rear direction are the same as
those in the 20th embodiment.
[0171] With the 21st embodiment, it is possible to obtain a mobile telephone apparatus which
has a small size and can decrease degradation in communication performance due to
the close positional relationship between the human body and the front surface of
the casing 1. Furthermore, according to the 21st embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0172] The structure of the 21st embodiment may be modified as in the first embodiment,
the 16th embodiment or the 20th embodiment.
[0173] The antenna 45 may be contained in the upper casing 30 or the lower casing 31.
(22nd Embodiment)
[0174] A mobile telephone apparatus according to a 22nd embodiment of the present invention
will now be described with reference to FIG. 41. In FIG. 41, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 41 shows only the structure of
an antenna 46 that is built in the mobile telephone apparatus according to the 22nd
embodiment.
[0175] As is shown in FIG. 41, the mobile telephone apparatus according to the 22nd embodiment
includes the antenna 46 built in the casing 1. The antenna 46 includes the dipole
antenna 8, opposed element 10, and parasitic elements 42 and 43.
[0176] Specifically, the antenna 46 includes the same elements as those of the antenna 41
of the 19th embodiment. The parasitic elements 42 and 43 are disposed in the second
imaginary plane. The parasitic elements 42 and 43 are line-symmetric with respect
to the symmetric axis A3.
[0177] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
46 emits radiation similarly with the 19th embodiment.
[0178] In the 22nd embodiment, the thickness of the antenna 46 in the front-and-rear direction
and the thickness of the casing 1 in the front-and-rear direction are the same as
those in the 20th embodiment.
[0179] With the 22nd embodiment, it is possible to obtain a mobile telephone apparatus which
has a small size and can decrease degradation in communication performance due to
the close positional relationship between the human body and the front surface of
the casing 1. Furthermore, according to the 22nd embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0180] The structure of the 22nd embodiment may be modified as in the first embodiment,
the 16th embodiment or the 20th embodiment.
[0181] The antenna 46 may be contained in the upper casing 30 or the lower casing 31.
(23rd Embodiment)
[0182] A mobile telephone apparatus according to a 23rd embodiment of the present invention
will now be described with reference to FIG. 42. In FIG. 42, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 42 shows only the structure of
an antenna 47 that is built in the mobile telephone apparatus according to the 23rd
embodiment.
[0183] As is shown in FIG. 42, the mobile telephone apparatus according to the 23rd embodiment
includes the antenna 47 built in the casing 1. The antenna 47 includes a dipole antenna
48, an opposed element 49, and parasitic elements 50 and 51.
[0184] The dipole antenna 48, opposed element 49 and parasitic elements 50 and 51 are all
formed of flat-plate conductor materials. The dipole antenna 48 is formed to have
a base portion 48a and bent portions 48b and 48c. The bent portions 48b and 48c are
bent from both ends of the base portion 48a at right angles and extend in the same
direction. A major surface of the base portion 48a faces in the front-and-rear direction.
Major surfaces of the bent portions 48b and 48c face in the right-and-left direction.
Like the dipole antenna 48, the opposed element 49 is configured to have a base portion
49a and bent portions 49b and 49c, the parasitic element 50 is configured to have
a base portion 50a and bent portions 50b and 50c, and the parasitic element 51 is
configured to have a base portion 51a and bent portions 51b and 51c.
[0185] The dipole antenna 48, opposed element 49 and parasitic elements 50 and 51 are disposed
with the same positional relationship as the dipole antenna 8, opposed element 10
and parasitic elements 42 and 43 in the 19th embodiment. However, the base portions
48a, 49a, 50a and 51a are disposed in the same imaginary plane, and the bent portions
48b, 48c, 49b, 49c, 50b, 50c, 51b and 51c are disposed in the same direction.
[0186] When power is fed to the dipole antenna 48 from the power feed means 6, the antenna
47 emits radiation similarly with the 19th embodiment.
[0187] In the 23rd embodiment, the bent portions 48b, 48c, 49b, 49c, 50b, 50c, 51b and 51c
are projected rearward, relative to the base portions 48a, 49a, 50a and 51a. Consequently,
the thickness of the antenna 47 in the front-and-rear direction is larger than that
of the antenna 41 of the 19th embodiment. However, the antenna 47 can efficiently
be accommodated in the casing 1 by arranging the bent portions 48b, 48c, 49b, 49c,
50b, 50c, 51b and 51c along the side faces of the casing 1. Thereby, the effective
mounting area for disposing other components such as a display can be increased.
[0188] Thus, with the 23rd embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 23rd embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0189] The structure of the 23rd embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0190] In the 23rd embodiment, the bent portions 48b, 48c, 49b, 49c, 50b, 50c, 51b and 51c
may be projected forward, relative to the base portions 48a, 49a, 50a and 51a. In
addition, the major surfaces of the base portions 48a, 49a, 50a and 51a may not be
at right angles with the major surfaces of the bent portions 48b, 48c, 49b, 49c, 50b,
50c, 51b and 51c.
[0191] The antenna 47 may be contained in the upper casing 30 or the lower casing 31.
(24th Embodiment)
[0192] A mobile telephone apparatus according to a 24th embodiment of the present invention
will now be described with reference to FIG. 43. In FIG. 43, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 43 shows only the structure of
an antenna 52 that is built in the mobile telephone apparatus according to the 24th
embodiment.
[0193] As is shown in FIG. 43, the mobile telephone apparatus according to the 24th embodiment
includes the antenna 52 built in the casing 1. The antenna 52 includes a dipole antenna
53, an opposed element 54, and parasitic elements 55 and 56.
[0194] The dipole antenna 53, opposed element 54 and parasitic elements 55 and 56 are all
formed of flat-plate conductor materials. The dipole antenna 53 is formed to have
a base portion 53a and bent portions 53b and 53c. The bent portions 53b and 53c are
bent.from both ends of the base portion 53a at right angles and extend in the same
direction. A major surface of the base portion 53a faces in the up-and-down direction.
Major surfaces of the bent portions 53b and 53c face in the right-and-left direction.
Like the dipole antenna 53, the opposed element 54 is configured to have a base portion
54a and bent portions 54b and 54c, the parasitic element 55 is configured to have
a base portion 55a and bent portions 55b and 55c, and the parasitic element 56 is
configured to have a base portion 56a and bent portions 56b and 56c.
[0195] The dipole antenna 53, opposed element 54 and parasitic elements 55 and 56 are disposed
with the same positional relationship as the dipole antenna 8, opposed element 10
and parasitic elements 42 and 43 in the 19th embodiment.
[0196] When power is fed to the dipole antenna 53 from the power feed means 6, the antenna
52 emits radiation similarly with the 19th embodiment.
[0197] In the 24th embodiment, the dipole antenna 53, opposed element 54 and parasitic elements
55 and 56 have thickness in the front-and-rear direction. Consequently, the thickness
of the antenna 52 in the front-and-rear direction is larger than that of the antenna
41 of the 19th embodiment. However, the antenna 52 can efficiently be accommodated
in the casing 1 by arranging the bent portions 53b, 53c, 54b, 54c, 55b, 55c, 56b and
56c along the side faces of the casing 1. Thereby, the effective mounting area for
disposing other components such as a display can be increased.
[0198] Thus, with the 24th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 24th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0199] The structure of the 24th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0200] The antenna 52 may be contained in the upper casing 30 or the lower casing 31.
(25th Embodiment)
[0201] A mobile telephone apparatus according to a 25th embodiment of the present invention
will now be described with reference to FIG. 44. In FIG. 44, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 44 shows only the structure of
an antenna 57 that is built in the mobile telephone apparatus according to the 25th
embodiment.
[0202] As shown in FIG. 44, the mobile telephone apparatus according to the 25th embodiment
includes the antenna 57 built in the casing 1. The antenna 57 includes the dipole
antenna 8, opposed element 10, and parasitic elements 58 and 59. Specifically, the
antenna 57 is formed by adding the parasitic elements 58 and 59 to the antenna 9 of
the fourth embodiment.
[0203] The parasitic element 58 is formed of a conductor material so as to have a base portion
58a, a pair of first bent portions 58b and 58c, and a pair of second bent portions
58d and 58e. The base portion 58a is longer than the base portion 8a. The first bent
portions 58b and 58c are bent from both ends of the base portion 58a at right angles
and extend in the same direction. The first bent portions 58b and 58c have the same
length. The second bent portions 58d and 58e are bent at right angles from the ends
of the first bent portions 58b and 58c and extend toward each other. The parasitic
element 59, like the parasitic element 58, is formed to have a base portion 59a, a
pair of first bent portions 59b and 59c, and a pair of second bent portions 59d and
59e.
[0204] The parasitic elements 58 and 59 are arranged along the opposed axis A2. An imaginary
plane in which all portions of the parasitic element 58 are positioned and an imaginary
plane in which all portions of the parasitic element 59 are positioned are opposed
to each other. These two imaginary planes are perpendicular to the imaginary plane
in which the dipole antenna 8 and opposed element 10 are positioned. In addition,
the bent portions 8b, 8c, 10b and 10c pass through these two imaginary planes. The
parasitic element 58 is line-symmetric with respect to a symmetric axis M1, and the
parasitic element 59 is line-symmetric with respect to a symmetric axis M2. The symmetric
axes M1 and M2 intersect at right angles with the symmetric axis A2 and extend in
the front-and-rear direction.
[0205] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
57 emits radiation similarly with the 17th embodiment.
[0206] In the 25th embodiment, the parasitic elements 58 and 59 have thickness in the front-and-rear
direction. Consequently, the thickness of the antenna 57 in the front-and-rear direction
is larger than that of the antenna 39 of the 17th embodiment. However, the antenna
57 can efficiently be accommodated in the casing 1 by arranging the bent portions
58b, 58c, 58d, 58e, 59b, 59c, 59d and 59e along the side faces of the casing 1. Thereby,
the effective mounting area for mounting other components such as a display can be
increased.
[0207] Thus, with the 25th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 25th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0208] The structure of the 25th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0209] The antenna 57 may be contained in the upper casing 30 or the lower casing 31.
(26th Embodiment)
[0210] A mobile telephone apparatus according to a 26th embodiment of the present invention
will now be described with reference to FIG. 45. In FIG. 45, the structural elements
common to those shown in the preceding Figures are denoted by like reference numerals,
and a detailed description thereof is omitted. FIG. 45 shows only the structure of
an antenna 60 that is built in the mobile telephone apparatus according to the 26th
embodiment.
[0211] As shown in FIG. 45, the mobile telephone apparatus according to the 26th embodiment
includes the antenna 60 built in the casing 1. The antenna 60 includes the dipole
antenna 8, opposed element 10, shorting elements 23 and 24, and parasitic elements
42 and 43. Specifically, the antenna 60 is formed by adding the parasitic elements
42 and 43 to the antenna 22 of the ninth embodiment.
[0212] The parasitic element 42 is disposed inside the dipole antenna 8 such that the base
portion 42a and bent portions 42b and 42c are parallel to the base portion 8a and
bent portions 8b and 8c, respectively. The parasitic element 43 is disposed inside
the opposed element 10 such that the base portion 43a and bent portions 43b and 43c
are parallel to the base portion 10a and bent portions 10b and 10c, respectively.
[0213] The parasitic elements 42 and 43 are disposed in the imaginary plane in which the
dipole antenna 8 and opposed element 10 are positioned. The parasitic elements 42
and 43 are in line-symmetry with respect to the symmetric axis A2.
[0214] When power is fed to the dipole antenna 8 from the power feed means 6, the antenna
60 emits radiation, similarly with the 19th embodiment. In addition, by the functions
of the shorting elements 23 and 24, the same advantages as with the ninth embodiment
can be obtained.
[0215] Thus, with the 26th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 26th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0216] The structure of the 26th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0217] The antenna 60 may be contained in the upper casing 30 or the lower casing 31.
[0218] The VSWR in the case where the antenna 60 is contained in the upper casing 30 was
measured. FIG. 46 shows the measurement result in which two resonance points are obtained.
In FIG. 46, "Open" indicates a measurement result in the state in which the upper
casing 30 and lower casing 31 are opened, and "Close" indicates a measurement result
in the state in which the upper casing 30 and lower casing 31 are closed.
[0219] A radiation pattern of the antenna 60 relating to 1920 MHz, which is a frequency
near one of the resonance points shown in FIG. 46, was simulated and radiation patterns
as shown in FIGS. 47A, 47B and 47C were obtained. In addition, a radiation pattern
of the antenna 60 relating to 2170 MHz, which is a frequency near the other resonance
point shown in FIG. 46, was simulated and radiation patterns as shown in FIGS. 47D,
47E and 47F were obtained. The radiation patterns in FIGS. 47A and 47D were obtained
with reference to the up-and-down axis. The radiation patterns in FIGS. 47B and 47E
were obtained with reference to the front-and-rear axis. The radiation patterns in
FIGS. 47C and 47F were obtained with reference to the right-and-left axis. In these
examples, it is assumed that the antenna 60 is designed such that the vertically polarized
wave component is dominant.
[0220] As is shown in these Figures, a null of a radiation pattern is created in the forward
direction in each of the cases of 1920 MHz and 2170 MHz. Therefore, a decrease in
radiation efficiency due to the effect of the human body can be avoided.
(27th Embodiment)
[0221] A mobile telephone apparatus according to a 27th embodiment of the present invention
will now be described with reference to FIG. 48 and FIG. 49. In FIGS. 48 and 49, the
structural elements common to those shown in the preceding Figures are denoted by
like reference numerals, and a detailed description thereof is omitted. FIG. 48 and
FIG. 49 show only the structure of an antenna 61, 66 built in the mobile telephone
apparatus according to the 27th embodiment.
[0222] As is shown in FIG. 48, the wireless communication apparatus according to the 27th
embodiment includes an antenna 61. The antenna 61 includes a dipole antenna 62, an
opposed element 63 and shorting elements 64 and 65.
[0223] The dipole antenna 62 is formed of a conductor material so as to have a base portion
62a and bent portions 62b and 62c. The bent portions 62b and 62c are bent from both
ends of the base portion 62a at right angles and extend in the same direction. The
bent portions 62b and 62c are further bent at right angles so as to extend toward
each other. Then, the bent portions 62b and 62c are folded so as to extend away from
each other. Finally, distal end portions of the bent portions 62b and 62c are bent
at right angles so as to approach the base portion 62a. The opposed element 63, like
the dipole antenna 62, is formed to have a base portion 63a and bent portions 63b
and 63c.
[0224] The dipole antenna 62 and opposed element 63 are disposed such that the base portion
62a and base portion 63a have the same positional relationship as the dipole antenna
3 and opposed element 4 in the first embodiment. The dipole antenna 62 and opposed
element 63 are disposed such that the bent portions 62b and 62c are situated away
from the bent portions 63b and 63c. The dipole antenna 62 and opposed element 63 are
arranged such that the imaginary plane in which the base portions 62a and 63a are
positioned is parallel to the front surface of the casing 1.
[0225] The shorting element 64 is formed of a conductor material so as to have a pair of
parallel portions 64a and 64b and a portion 64c that linearly connects both ends of
the portions 64a and 64b. The distance between the portions 64a and 64b is equal to
the distance between the base portions 62a and 63a. Like the shorting element 64,
the shorting element 65 is formed of conductor material so as to have portions 65a,
65b and 65c. The shorting elements 64 and 65 are connected to the base portions 62a
and 63a so as to project rearward, relative to the base portions 62a and 63a.
[0226] The antenna 66 shown in FIG. 49 is a variation of the antenna 61. The antenna 66
includes the dipole antenna 62, opposed element 63 and shorting elements 67 and 68.
Specifically, the antenna 66 includes the shorting elements 67 and 68 in place of
the shorting elements 64 and 65 of the antenna 61.
[0227] The shorting elements 67 and 68, like the shorting elements 64 and 65, are connected
to the base portions 62a and 63a so as to project rearward, relative to the base portions
62a and 63a. However, the shorting elements 67 and 68 are formed so as to protrude
upward and downward.
[0228] With the configuration of the 27th embodiment, the line lengths of the bent portions
62b, 62c, 63b and 63c are increased and these portions are disposed along the periphery
of the board 25, as shown in FIGS. 48 and 49. Thereby, these portions can efficiently
be accommodated in the casing 1.
[0229] In addition, the shorting elements 64 and 65 and the shorting elements 67 and 68
are disposed along the periphery of the board 25, as shown in FIGS. 48 and 49. Thereby,
these shorting elements can efficiently be accommodated in the casing 1. The shorting
element 67, 68 can have a greater line length than the shorting element 20, 21, 23,
24, 64, 65.
[0230] Thus, with the 27th embodiment, it is possible to obtain a mobile telephone apparatus
which has a small size and can decrease degradation in communication performance due
to the close positional relationship between the human body and the front surface
of the casing 1. Furthermore, according to the 27th embodiment, both the horizontally
polarized wave component and vertically polarized wave component can fully be radiated,
and a broad frequency band is realized.
[0231] The structure of the 27th embodiment may be modified as in the first embodiment or
the 16th embodiment.
[0232] The antenna 61, 66 may be contained in the upper casing 30 or the lower casing 31.
1. A wireless communication apparatus which has a casing (1) having a thickness and a
first surface perpendicular to a direction of the thickness, the wireless communication
apparatus
characterized in that comprising:
a dipole antenna (3, 8, 14, 48, 53, 62) including a first base portion (8a, 14a, 48a,
53a, 62a); and
an opposed element (4, 10, 15, 49, 54, 63) formed of a conductor material and including
a second base portion (10a, 15a, 49a, 54a, 63a),
the dipole antenna (3, 8, 14, 48, 53, 62) and the opposed element (4, 10, 15, 49,
54, 63) being disposed within the casing (1) such that the dipole antenna (3, 8, 14,
48, 53, 62) and the opposed element (4, 10, 15, 49, 54, 63) extend in an imaginary
plane that is substantially parallel to the first surface, and the first base portion
(8a, 14a, 48a, 53a, 62a) and the second base portion (10a, 15a, 49a, 54a, 63a) are
opposed to each other.
2. A wireless communication apparatus which has a first casing (30) and a second casing
(31) that are coupled to each other, the first casing (30) having a first thickness
and a first surface perpendicular to a direction of the thickness, and the second
casing (31) having a second thickness and a second surface perpendicular to a direction
of the thickness, the wireless communication apparatus being
characterized by comprising:
a dipole antenna (3, 8, 14, 48, 53, 62) including a first base portion (8a, 14a, 48a,
53a, 62a), the dipole antenna (3, 8, 14, 48, 53, 62) being disposed within the first
casing (30) such that the dipole antenna (3, 8, 14, 48, 53, 62) extends in an imaginary
plane that is substantially parallel to the first surface and the second surface;
and
an opposed element (4, 10, 15, 49, 54, 63) formed of a conductor material and including
a second base portion (10a, 15a, 49a, 54a, 63a), the opposed element (4, 10, 15, 49,
54, 63) being disposed within the second casing(31) such that the opposed element
(4, 10, 15, 49, 54, 63) extends in the imaginary plane and the second base portion
(10a, 15a, 49a, 54a, 63a) is opposed to the first base portion(8a, 14a, 48a, 53a,
62a).
3. A wireless communication apparatus which has a first casing (30) and a second casing
(31) that are coupled to each other, and a flexible board (33) that electrically connects
the first casing (30) and the second casing (31), the first casing (30) having a thickness
and a first surface perpendicular to a direction of the thickness, the wireless communication
apparatus being
characterized by comprising:
a dipole antenna (3, 8, 14, 48, 53, 62) including a first base portion (8a, 14a, 48a,
53a, 62a), the dipole antenna (3, 8, 14, 48, 53, 62) being disposed within the first
casing (30) such that the dipole antenna (3, 8, 14, 48, 53, 62) extends in an imaginary
plane that is substantially parallel to the first surface; and
an opposed element (4, 10, 15, 35, 49, 54, 63) formed of a conductor material and
including a second base portion (10a, 15a, 35a, 49a, 54a, 63a), the opposed element
(4, 10, 15, 35, 49, 54, 63) being disposed on the flexible board (33) such that the
second base portion (10a, 15a, 35a, 49a, 54a, 63a) is opposed to the first base portion
(8a, 14a, 48a, 53a, 62a).
4. The wireless communication apparatus according to any one of claims 1 to 3, characterized in that the dipole antenna (8, 14, 48, 53, 62) further includes a pair of first bent portions
(8b, 8c, 14b, 14c, 48b, 48c, 53b, 53c, 62b, 62c) that extend in the same direction
from both ends of the first base portion (8a, 14a, 48a, 53a, 62a).
5. The wireless communication apparatus according to claim 4, characterized in that the opposed element (4, 10, 15, 49, 54, 63) further includes a pair of second bent
portions (10b, 10c, 15b, 15c, 49b, 49c, 54b, 54c, 63b, 63c) that extend from both
ends of the second base portion (10a, 15a, 49a, 54a, 63a) in a direction opposite
to the direction in which the first bent portions (8b, 8c, 14b, 14c, 48b, 48c, 53b,
53c, 62b, 62c) extend.
6. The wireless communication apparatus according to claim 5,
characterized by further comprising:
a first short element (17a) that short-circuits the pair of the first bent portions
(8b, 8c); and
a second short element (18a) that short-circuits the pair of the second bent portions
(10b, 10c).
7. The wireless communication apparatus according to claim 5, characterized by further comprising a pair of short elements (20, 21, 23, 24, 64, 67) that short-circuit
the dipole antenna (8, 62) and the opposed element (10, 63).
8. The wireless communication apparatus according to any one of claims 1 to 3, characterized in that the first base portion (8a, 14a, 48a, 53a, 62a) and the second base portion (10a,
15a, 49a, 54a, 63a) are substantially in line-symmetry with respect to an imaginary
opposed axis (A1) that is located at a middle point between the first base portion
(8a, 14a, 48a, 53a, 62a) and the second base portion (10a, 15a, 49a, 54a, 63a).
9. The wireless communication apparatus according to any one of claims 1 to 3, characterized in that each of the dipole antenna (3, 8, 14, 48, 53, 62) and the opposed element (4, 10,
15, 49, 54, 63) is in line-symmetry with respect to an imaginary symmetric axis (A2)
that extends in a direction of arrangement of the first base portion (8a, 14a, 48a,
53a, 62a) and the second base portion (10a, 15a, 49a, 54a, 63a) and passes through
a middle point of the first base portion (8a, 14a, 48a, 53a, 62a).
10. The wireless communication apparatus according to any one of claims 1 to 3, characterized in that a first parasitic element (37, 42, 50, 55, 58) formed of a conductor material and
including a third base portion (37a, 42a, 50a, 55a, 58a) is disposed such that the
third base portion (37a, 42a, 50a, 55a, 58a) is opposed to the first base portion
(8a, 14a, 48a, 53a, 62a), and
a second parasitic element (38, 43, 51, 56, 59) formed of a conductor material
and including a fourth base portion (38a, 43a, 51a, 56a, 59a) is disposed such that
the fourth base portion (38a, 43a, 51a, 56a, 59a) is opposed to the second base portion
(10a, 15a, 49a, 54a, 63a).
11. The wireless communication apparatus according to claim 10, characterized in that the first parasitic element (37, 42, 50, 55, 58) further includes a pair of third
bent portions (, 42b, 42c, 50b, 50c, 55b, 55c, 58b, 58c) that extend in the same direction
from both ends of the third base portion (37a, 42a, 50a, 55a, 58a).
12. The wireless communication apparatus according to claim 11, characterized in that the second parasitic element (38, 43, 51, 56, 59) further includes a pair of fourth
bent portions (43a, 43b, 51a, 51b, 56a, 56b, 59a, 59b) that extend from both ends
of the fourth base portion (38a, 43a, 51a, 56a, 59a) in a direction opposite to the
direction in which the third bent portions (42b, 42c, 50b, 50c, 55b, 55c, 58b, 58c)
extend.
13. The wireless communication apparatus according to claim 4, characterized in that a first parasitic element (37) formed of a conductor material and including a third
base portion is disposed such that the third base portion is opposed to one of the
pair of the first bent portions (8b, 8c), and
a second parasitic element (38) formed of a conductor material and including a
fourth base portion is disposed such that the fourth base portion is opposed to the
other of the pair of the first bent portions (8b, 8c).