BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a vehicular antenna capable of either transmission
and reception, or reception in the car phone band and GPS band, and more particularly
to a vehicular antenna well-suited for use as a roof antenna, which is mounted to
the roof of a vehicle.
2. Description of the Related Art
[0002] There are a variety of antennas that can be mounted to a vehicle, but since mounting
an antenna to the roof, which is the highest point on a vehicle, can enhance receptivity,
the roof-mounted roof antenna has been preferred for some time. Further, car navigation
systems that make use of the global positioning system (GPS), and car phones have
become popular recently, and there is demand for equipping vehicles with a GPS antenna
used with a car navigation system, and a telephone antenna used with a car phone.
[0003] Now, since installing each of a plurality of types of antennas separately on a vehicle
causes problems from the standpoint of design, and also makes installation work and
maintenance complicated, a vehicular antenna, which provides a car phone antenna portion
and a GPS antenna portion in a single antenna case, is desirable.
[0004] An example of the constitution of this type of vehicular antenna is shown in Fig.
14. The vehicular antenna 100 shown in Fig. 14 comprises a GPS antenna 104, which
receives GPS signals, and a telephone antenna 105, which is used by a car phone. These
2 types of antennas are installed in an antenna case comprising a conductive metal
base 103, and a synthetic plastic cover 102, which is attached by fitting same together
with this metal base 103. Furthermore, the telephone antenna 105 is a rod-shaped antenna,
and is screwed into a mounting portion of the cover 102. Then, the telephone antenna
105 is electrically connected to a circuit board 106, which incorporates a matching
circuit. Further, the GPS antenna 104 is housed inside a storage portion formed in
the metal base 103.
[0005] However, in the above-described vehicular antenna 100, because the rod-shaped telephone
antenna 105 is provided in a standing condition relative to the cover 102, the overall
height is high. Consequently, mounting this vehicular antenna 100 to a vehicle can
cause problems from the standpoint of design, and can cause problems from the standpoint
of operation. Further, it gives rise to the danger of the protruding telephone antenna
105 being bent or broken off by an obstacle.
[0006] Now then, to make the vehicular antenna 100 shown in Fig. 14 smaller, the rod-shaped
telephone antenna 105 can be made smaller. One method that comes to mind for making
the telephone antenna 105 smaller is to use the helical antenna 110 shown in Fig.
15 as a telephone antenna 105.
[0007] However, if the antenna height H2 of a helical antenna 110 is held in check, antenna
impedance decreases, making it difficult to achieve a match with the electric supply
line, thus prohibiting antenna height H2 from being lowered too much. Actually, if
the wavelength of the targeted frequency is treated as λ, an antenna height H2 of
around 3λ/16-λ/4 is required, indicating that the helical antenna 110 cannot be made
too small.
[0008] Furthermore, if the antenna height H2 of a helical antenna 110 exceeds 3λ/16, the
voltage standing wave ratio (VSWR) characteristics thereof constitute the characteristics
shown as "Conventional" in Fig. 12, and the operable frequency range F1 is narrowband,
thus making it unsuitable as a telephone antenna, which requires broadband. And furthermore,
if the antenna height H2 of a helical antenna 110 is less than 3λ/16, the VSWR characteristics
thereof constitute the characteristics shown as "Conventional" in Fig. 13. That is,
the VSWR is 3 or larger, causing antenna gain to decrease greatly.
[0009] Further, one method that comes to mind for making a telephone antenna 105 smaller
is to use a top-loaded antenna 120 shown in Fig. 16 (a), (b) as a telephone antenna
105. This top-loaded antenna 120 constitutes an element portion 120b, which is arranged
in a standing condition perpendicular to a substrate 120c, and a circular top load
portion 120a which is provided at the end of the element portion 120b. In accordance
with providing the top load portion 120a at the end of the element portion 120b, it
is possible to keep the antenna height H3 of the top-loaded antenna 120 low. Also,
antenna impedance does not decrease, and matching can be readily achieved. However,
when the antenna height H3 is lowered to where the top-loaded antenna 120 can be housed
inside a cover 102, the diameter D5 of the top load portion 120a increases, requiring
an antenna case with a large internal volume. In the end, the vehicular antenna 100
cannot be made smaller.
[0010] Accordingly, an object of the present invention is to provide a compact vehicular
antenna, which is capable of storing a GPS antenna portion and a telephone antenna
portion inside a compact antenna case.
SUMMARY OF THE INVENTION
[0011] To achieve the above-mentioned object, the vehicular antenna of the present invention
comprises a telephone antenna portion capable of receiving radiotelephony bands; a
circuit board, which is equipped at the least with matching means, and to which this
telephone antenna portion is mounted in a fixed condition; a GPS antenna portion;
a conductive base; and a cover, which is attached by fitting same together with this
base, and comprises an antenna case, inside which the above-mentioned telephone antenna
portion, the above-mentioned circuit board, and the above-mentioned GPS antenna portion
are stored, and the above-mentioned telephone antenna portion is constituted from
an element portion, and a top load portion, which is disposed at the end of this element
portion, and which is bent downward.
[0012] Further, with the above-described vehicular antenna, the above-mentioned top load
portion can be configured as a downward sloping umbrella shape, or can be bent more
than once so that the end portion of the above-mentioned top load portion forms a
rough orthogonal, or the above-mentioned top load portion can be configured as a frame-only
skeleton constitution. Furthermore, one end of the element portion can be connected
to a prescribed location on the above-mentioned element portion, while the other end
of the grand plane is provided with a matching stub connected to a ground, and a compacting
coil is inserted in the above-mentioned element portion.
[0013] According to a present invention such as this, the storing of a GPS antenna portion
and a telephone antenna portion inside an antenna case enables the realization of
a vehicular antenna, which lacks a protruding element section, and also enables the
realization of a vehicular antenna which will not be broken off or bent by an obstacle.
[0014] Further, because the top load portion of the telephone antenna portion is bent downward,
the space between the top load portion and the ground plane is narrowed, thereby increasing
the capacity resulting from the top load portion and the ground plane. In accordance
therewith, since the diameter of the top load portion can be kept small, the antenna
height can be lowered, and a compact telephone antenna portion can be achieved.
[0015] In this manner, with the vehicular antenna of the present invention, it becomes possible
to store a telephone antenna portion inside a compact antenna case, and the overall
size of the vehicular antenna can be made small, thereby eliminating to the utmost
problems from the standpoint of design when the vehicular antenna is mounted to a
vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Fig. 1 is a top view, plan view showing the constitution of an aspect of the embodiment
of the vehicular antenna of the present invention;
Fig. 2 is a diagram showing a breakout plan view of the constitution of an aspect
of the embodiment of the vehicular antenna of the present invention;
Fig. 3 is a diagram showing an oblique view of an aspect of the embodiment of the
vehicular antenna of the present invention with the cover removed;
Fig. 4 is a diagram showing an example of a first constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 5 is a diagram showing an example of a second constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 6 is a diagram showing an example of a third constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 7 is a diagram showing an example of a fourth constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 8 is a diagram showing an example of a fifth constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 9 is a diagram showing an example of a sixth constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 10 is a diagram showing an example of a seventh constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 11 is a diagram showing an example of an eighth constitution of a telephone antenna
in a vehicular antenna of an aspect of the embodiment of the present invention;
Fig. 12 is a diagram comparing the VSWR characteristics of a telephone antenna in
a vehicular antenna of an aspect of the embodiment of the present invention with those
of a conventional antenna;
Fig. 13 is a diagram comparing the VSWR characteristics of a telephone antenna in
a vehicular antenna of an aspect of the embodiment of the present invention with those
of a conventional antenna;
Fig. 14 is a cross-sectional view showing the constitution of a conventional vehicular
antenna;
Fig. 15 is a diagram showing the constitution of a helical antenna used as a telephone
antenna in a conventional vehicular antenna; and
Fig. 16 is a diagram showing the constitution of a top-loaded antenna used as a telephone
antenna in a conventional vehicular antenna.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The constitution of an aspect of the embodiment of a vehicular antenna of the present
invention is shown in Fig. 1 (a), (b) through Fig. 3. Fig. 1 (a) is a top view of
a vehicular antenna, Fig. 1 (b) is a plan view thereof, Fig. 2 shows a breakout plan
view, and Fig. 3 is an oblique view with the cover removed.
[0018] As shown in Fig. 1, a vehicular antenna 1 of the present invention comprises an elliptical
conductive metal base 3, and an antenna case, comprising a synthetic plastic cover
2 attached by fitting same together with this metal base 3. As shown in Fig. 2, a
flexible pad 8 is arranged on the bottom surface of this metal base 3, and the vehicular
antenna 1 is mounted to a vehicle. The vehicular antenna 1 does not have an element
or other portion, which protrudes from the antenna case.
[0019] Furthermore, a mounting screw portion 3a is formed in a protruding condition on the
back side of the metal base 3. This mounting screw portion 3a is inserted into a mounting
hole formed in a vehicle, and mounts the vehicular antenna 1 to the vehicle in a fixed
condition by screwing in the mounting screw. In this mounting screw portion 3a, there
is provided a through hole, which is a slit formed parallel to the axis of the mounting
screw portion 3a, and this through hole is used to guide a GPS cable 10 and a telephone
cable 11 into the antenna case from externally.
[0020] The end of the GPS cable is equipped with a connector 10a, which connects to a GPS
instrument, and the end of the telephone cable is equipped with a connector 11a, which
connects to a car phone.
[0021] As shown in Fig. 2 by breaking out the cover 2 and metal base 3, a GPS antenna portion
4, which receives GPS signals, and a telephone antenna portion 5 for a car phone are
stored inside an antenna case. This GPS antenna portion 4 is housed inside a GPS antenna
storage portion 3b formed in the metal base 3. And then, the telephone antenna portion
5 is connected electrically, and mounted in a fixed condition mechanically to a matching
circuit-embedded circuit board 6, which is shown in Figs. 2, 3. Then, this circuit
board 6 is mounted in a fixed condition to the metal base 3. Further, the GPS cable
10, which is guided inside the antenna case, is connected to the GPS antenna portion
4, and the telephone cable 11 is connected to the circuit board 6.
[0022] Furthermore, the GPS antenna storage portion 3b constitutes a shape, in which a frame
capable of storing the rectangular-shaped GPS antenna portion 4 is formed with 4 sides,
and the GPS antenna portion 4 is stored in this GPS antenna storage portion 3b via
a waveform wave spring 4a. And then, although not shown in the figure, when the cover
2 is attached by fitting same together with the metal base 3, the GPS antenna portion
4 is held in place inside the GPS antenna storage portion 3b by pressure applied thereto
by a pressure protrusion formed on the inner side of the cover 2.
[0023] Further, when the GPS cable 10 and telephone cable 11 are guided out from the through
hole in the mounting screw portion 3a, as shown in Fig. 2, in addition to being pulled
out sideways from inside the slit formed parallel to the axis of the mounting screw
portion 3a, these cables 10, 11 can also be pulled out perpendicular thereto as indicated
by the 2-dot chain line. In accordance therewith, the GPS cable 10 and telephone cable
11 can be pulled out by tailoring same to the structure of the vehicle to which the
vehicular antenna is to be mounted.
[0024] The telephone antenna portion 5 comprises an umbrella-shaped top load portion 5a,
which is bent downward as shown in the figure, for example, and a linear element 5b,
and a matching stub 5e is disposed so as to connect between midway on the element
5b and a ground pattern of the circuit board 6. This matching stub 5e is for achieving
matching between the telephone antenna portion 5 and the telephone cable 11, and the
top load portion 5a is housed in the semi-spherical bulge portion of the cover 2.
Further, as shown in Fig. 2, a T-shaped pin 6a is provided so as to pass through from
the back surface of the circuit board 6 and protrude to the front surface, and the
element portion 5b, which is formed from a metal pipe, is configured by being fitted
together by insertion with the protruding T-shaped pin 6a. Furthermore, the tip of
the element portion 5b is fitted by insertion through the through hole disposed roughly
in the center of the umbrella-shaped top load portion 5a, and mounted in a fixed condition
using solder or the like.
[0025] Various constitutions are possible for the telephone antenna portion 5, and the constitution
shown in Fig. 2 and Fig. 3 is one such example. Fig. 4 through Fig. 11 show examples
of other constitutions.
[0026] A first example of a constitution of a telephone antenna portion 5 is shown in Fig.
4. Fig. 4 (a) is a top view of a telephone antenna portion 5, and Fig. 4 (b) shows
a half section of a plan view thereof.
[0027] As shown in these diagrams, the telephone antenna portion 5 of the first constitution
example is constituted from a linear element portion 5b, and a circular top load portion
5a, which is disposed at the end of this element 5b, and which is bent downward so
as to form an umbrella shape. A flange-shaped top load mounting portion 5c is formed
at the end of the element portion 5b, and the top load portion 5a is mounted in a
fixed condition by solder to the top load mounting portion 5c. Further, at the bottom
end of the element portion 5b, a flange-shaped mounting portion 5d is formed, and
this mounting portion 5d is mounted in a fixed condition by solder to a pattern formed
in a circuit board 6. At this time, the element portion 5b is connected to a matching
circuit provided on the circuit board 6. Furthermore, when the circuit board 6 is
mounted to the metal base 3, the ground pattern of the circuit board 6 is connected
electrically to the metal base 3, and the metal base 3 is used as the ground plane
for the telephone antenna portion 5.
[0028] Because the top load portion 5a of this telephone antenna portion 5 is bent downward
so as to constitute an umbrella shape, the capacity formed between the metal base
3, which constitutes the ground plane, and the top load portion 5a is large, enabling
the diameter D2 of the top load portion 5a to be shortened. For example, when this
telephone antenna portion 5 is used as an antenna in a Global System for Mobile Communications
(GSM) system, which is one of the digital cellular systems, the diameter D2 of the
top load portion 5a becomes roughly 30mm, and the antenna height H1 becomes roughly
25.8mm. By comparison, when a conventional top-loaded antenna 120 of the same antenna
height, shown in Fig. 16, is used in a GSM system, the diameter D5 of the top load
portion 120a must be 40mm. The size of the diameter of top load portion 5a is thus
more than 30 percent smaller. Furthermore, the transmitting frequency of the GSM system
is set between 890-915 MHz, and the receiving frequency is set at between 935-960
MHz.
[0029] Next, a second example of a constitution of a telephone antenna portion 5 is shown
in Fig. 5. Fig. 5 (a) shows a top view of a telephone antenna portion 5, and Fig.
5 (b) shows a half section of a plan view thereof.
[0030] As shown in these diagrams, the telephone antenna portion 5 of the second constitution
example is constituted from a linear element portion 5b, and a circular top load portion
5a, which is disposed at the end of this element 5b. The end of this top load portion
5a is bent downward at roughly a right angle so that the cross-section thereof forms
an L shape. Then, a flange-shaped top load mounting portion 5c is formed at the end
of the element portion 5b, and the top load portion 5a is mounted in a fixed condition
by solder to the top load mounting portion 5c.
Further, at the bottom end of the element portion 5b, a flange-shaped mounting portion
5d is formed, and this mounting portion 5d is mounted in a fixed condition by solder
to a pattern formed in a circuit board 6. At this time, the element portion 5b is
connected to a matching circuit provided on the circuit board 6. Furthermore, when
the circuit board 6 is mounted to the metal base 3, the ground pattern of the circuit
board 6 is connected electrically to the metal base 3, and the metal base 3 is used
as the ground plane for the telephone antenna portion 5.
[0031] Because the top load portion 5a of this telephone antenna portion 5 is bent downward
at roughly a right angle, the capacity formed between the metal base 3, which constitutes
the ground plane, and the top load portion 5a is large, enabling the diameter D3 of
the top load portion 5a to be shortened. For example, when this telephone antenna
portion 5 is used as an antenna in a GSM system, the diameter D3 of the top load portion
5a becomes roughly 30mm, and the antenna height becomes roughly 25.8mm. Therefore,
the size of the diameter can be more than 30 percent shorter than that of a conventional
top-loaded antenna 120.
[0032] Next, a third example of a constitution of a telephone antenna portion 5, which is
an improved version of the second constitution example, is shown in Fig. 6. Fig. 6
(a) shows a top view of a telephone antenna portion 5, and Fig. 6 (b) shows a half
section of a plan view thereof.
[0033] As shown in these diagrams, the telephone antenna portion 5 of the third constitution
example is constituted from a linear element portion 5b, and a circular top load portion
5a, which is disposed at the end of this element portion 5b. The end of this top load
portion 5a is bent downward at roughly a right angle in 2 stages so that the cross-section
thereof forms a U shape. Then, a flange-shaped top load mounting portion 5c is formed
at the tip of the element portion 5b, and the top load portion 5a is mounted in a
fixed condition by solder to the top load mounting portion 5c. Further, at the bottom
end of the element portion 5b, a flange-shaped mounting portion 5d is formed, and
this mounting portion 5d is mounted in a fixed condition by solder to a pattern formed
in a circuit board 6. At this time, the element portion 5b is connected to a matching
circuit provided on the circuit board 6. Furthermore, when the circuit board 6 is
mounted to the metal base 3, the ground pattern of the circuit board 6 is connected
electrically to the metal base 3, and the metal base 3 is used as the ground plane
for the telephone antenna portion 5.
[0034] Because the top load portion 5a of this telephone antenna portion 5 is bent downward
in 2 stages at roughly right angles, the capacity formed between the metal base 3,
which constitutes the ground plane, and the top load portion 5a is large, enabling
the diameter D4 of the top load portion 5a to be shortened. For example, when this
telephone antenna portion 5 is used as an antenna in a GSM system, the diameter D4
of the top load portion 5a becomes roughly 25mm, and the antenna height becomes roughly
25.8mm. Therefore, the size of the diameter can be roughly 17% shorter than that of
the telephone antenna portion 5 of the second constitution example.
[0035] Next, a fourth example of a constitution of a telephone antenna portion 5 is shown
in Fig. 7. Fig. 7 (a) shows a top view of a telephone antenna portion 5, and Fig.
7 (b) shows a half section of a plan view thereof.
[0036] As shown in these figures, in the telephone antenna portion 5 of the fourth constitution
example, a matching stub 5e is provided on a linear element portion 5b, making matching
easy to achieve. One end of this matching stub 5e is connected to a prescribed location
of the element portion 5b, and the other end is connected to a ground pattern formed
in a circuit board 6. Furthermore, in Fig. 7, the top load portion 5a constitutes
a shape, which is bent downward so as to form an umbrella shape, but the shape of
the top load portion 5a can be made into a shape, in which the end is bent downward
at roughly a right angle (See Fig. 5), or the top load portion 5a can be made into
a shape, in which the end is bent downward in 2 stages at roughly right angles (See
Fig. 6).
[0037] Next, a fifth example of a constitution of a telephone antenna portion 5 is shown
in Fig. 8. Fig. 8 (a) shows a top view of a telephone antenna portion 5, and Fig.
8 (b) shows a half section of a plan view thereof.
[0038] As shown in these figures, in the telephone antenna portion 5 of the fifth constitution
example, a contracting coil 5f is inserted into a linear element portion 5b, making
it possible to further shorten the length of the element portion 5b. A matching stub
5e is also provided on the element portion 5b, making it easy to achieve matching
even though a contracting coil 5f has been inserted. One end of this matching stub
5e is connected to a prescribed location of the element portion 5b, and the other
end is connected to a ground pattern formed in a circuit board 6.
[0039] Furthermore, in Fig. 8, the top load portion 5a constitutes a shape, which is bent
downward so as to form an umbrella shape, but the shape of the top load portion 5a
can be made into a shape, in which the end is bent downward at roughly a right angle
(See Fig. 5), or the top load portion 5a can be made into a shape, in which the end
is bent downward in 2 stages at roughly right angles (See Fig. 6).
[0040] Next, a sixth example of a constitution of a telephone antenna portion 5 is shown
in Fig. 9. Fig. 9 (a) shows a top view of a telephone antenna portion 5, and Fig.
9 (b) shows a half section of a plan view thereof.
[0041] As shown in these figures, in the telephone antenna portion 5 of the sixth constitution
example, the top load portion 5a is a skeleton constitution of only the frame thereof.
Even when the top load portion 5a is a skeleton constitution like this, the diameter
of the top load portion 5a can be made smaller than in the past without the capacity
generated between the top load portion 5a and the ground plane being reduced.
[0042] Furthermore, in Fig. 9, the top load portion 5a constitutes a shape, which is bent
downward so as to form an umbrella shape, but the shape of the top load portion 5a
can be made into a shape, in which the end is bent downward at roughly a right angle
(See Fig. 5), or the top load portion 5a can be made into a shape, in which the end
is bent downward in 2 stages at roughly right angles (See Fig. 6), and this top load
portion 5a can also be made into a skeleton constitution.
[0043] Next, a seventh example of a constitution of a telephone antenna portion 5 is shown
in Fig. 10. Fig. 10 (a) shows a top view of a telephone antenna portion 5, and Fig.
10 (b) shows a half section of a plan view thereof.
[0044] As shown in these figures, in the telephone antenna portion 5 of the seventh constitution
example, a dielectric 7 fills in the space between the top load portion 5a and the
circuit board 6. In accordance therewith, the capacity generated between the top load
portion 5a and the ground plane increases in accordance with the dielectric constant
of the dielectric 7, enabling the diameter of the top load portion 5a to be made smaller.
[0045] Furthermore, in Fig. 10, the top load portion 5a constitutes a shape, which is bent
downward so as to form an umbrella shape, but the shape of the top load portion 5a
can be made into a shape, in which the end is bent downward at roughly a right angle
(See Fig. 5), or the top load portion 5a can be made into a shape, in which the end
is bent downward in 2 stages at roughly right angles (See Fig. 6), and a dielectric
7 can fill in the space between the top load portion 5a and the ground plane. Further,
the top load portion 5a can be formed by either depositing a thin film via evaporation
onto the surface of the dielectric 7, or by attaching a thin metal sheet to the surface
of the dielectric 7 using a viscous substance.
[0046] Next, an eighth example of a constitution of a telephone antenna portion 5 is shown
in Fig. 11. Fig. 11 (a) shows a top view of a telephone antenna portion 5, and Fig.
11 (b) shows a half section of a plan view thereof.
As shown in these figures, in the telephone antenna portion 5 of the eighth constitution
example, the inside of the dielectric 7, which fills in the space between the top
load portion 5a and the circuit board 6, is hollow. Even by so doing, the capacity
generated between the top load portion 5a and the ground plane increases in accordance
with the dielectric constant of the dielectric 7, enabling the diameter of the top
load portion 5a to be made smaller.
[0047] Furthermore, in Fig.ll, the top load portion 5a constitutes a shape, which is bent
downward so as to form an umbrella shape, but the shape of the top load portion 5a
can be made into a shape, in which the end is bent downward at roughly a right angle
(See Fig. 5), or the top load portion 5a can be made into a shape, in which the end
is bent downward in 2 stages at roughly right angles (See Fig. 6), and a dielectric
7 can fill in the space between the top load portion 5a and the ground plane. Further,
the top load portion 5a can be formed by either depositing a thin film via evaporation
onto the surface of the dielectric 7, or by attaching a thin metal sheet to the surface
of the dielectric 7 using a viscous substance.
[0048] In the thus constituted first constitution example through eighth constitution example,
the electrical characteristics of the telephone antenna portion 5 are practically
identical. For example, the VSWR frequency characteristics of the telephone antenna
portion 5 of the fourth constitution example shown in Fig. 7 are shown in Fig. 12
and Fig. 13.
[0049] Fig. 12 is VSWR characteristics when antenna height is made to exceed 3λ/16 (λ: targeted
frequency wavelength), and it was learned that, as indicated by "Present Invention"
in Fig. 12, the operable frequency range becomes broadband, making the fourth constitution
example well suited for use as a telephone antenna.
[0050] Further, Fig. 13 is VSWR characteristics when antenna height is less than 3λ/16,
and it was learned that, as indicated by "Present Invention" in Fig. 13, the frequency
range of a 2.0 or less VSWR becomes broadband, making the fourth constitution example
well suited for use as a telephone antenna.
[0051] Since the present invention is constituted as described above, a GPS antenna portion
and a telephone antenna portion can be housed inside an antenna case, enabling the
realization of a vehicular antenna without a protruding element part, and making it
possible to achieve a vehicular antenna, which will not be broken off or bent by an
obstacle.
[0052] Further, because the top load portion in the telephone antenna portion is bent downward,
the gap between the top load portion and the ground is narrowed, and the capacity
resulting from the top load portion and the ground is increased. In accordance therewith,
since the diameter of the top load portion can be kept small, the antenna height can
be lowered, and the telephone antenna portion can be made compact.
[0053] In this manner, because the vehicular antenna of the present invention makes it possible
to house a telephone antenna portion inside a compact antenna case, and enables the
overall vehicular antenna to be made compact, design problems are held to the minimum
even when same is mounted to a vehicle.