(19)
(11)EP 2 717 385 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
06.05.2020 Bulletin 2020/19

(21)Application number: 12762519.2

(22)Date of filing:  16.02.2012
(51)Int. Cl.: 
H01Q 9/28  (2006.01)
H01Q 19/30  (2006.01)
(86)International application number:
PCT/JP2012/001026
(87)International publication number:
WO 2012/164782 (06.12.2012 Gazette  2012/49)

(54)

ANTENNA APPARATUS

ANTENNENVORRICHTUNG

DISPOSITIF D'ANTENNE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 02.06.2011 JP 2011123934

(43)Date of publication of application:
09.04.2014 Bulletin 2014/15

(73)Proprietor: Panasonic Corporation
Osaka 571-8501 (JP)

(72)Inventors:
  • OHNO, Takeshi
    2-1-61, Shiromi, Chuo-ku Osaka 540-6207 (JP)
  • SHINKAI, Sotaro
    2-1-61, Shiromi, Chuo-ku Osaka 540-6207 (JP)

(74)Representative: Eisenführ Speiser 
Patentanwälte Rechtsanwälte PartGmbB Postfach 10 60 78
28060 Bremen
28060 Bremen (DE)


(56)References cited: : 
WO-A1-2008/120826
CA-A1- 2 596 025
JP-A- 2001 320 229
US-A1- 2008 272 976
WO-A2-2005/036694
JP-A- H07 245 525
JP-A- 2011 003 972
US-A1- 2009 213 024
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present invention relates to an antenna apparatus including a dipole antenna, and a wireless communication apparatus including the antenna apparatus.

    BACKGROUND ART



    [0002] A slot antenna has been known as an end-fire antenna according to a prior art. The slot antenna apparatus has a slot, which is formed at an edge of a ground conductor formed on a top surface of a dielectric substrate to intersect the edge, and a feeder line, which is formed on a reverse side of the dielectric substrate to intersect the slot. The feeder line is electromagnetically coupled to the slot, and a high-frequency signal transmitted via the feeder line excites the slot. In this case, an electric field appearing in the slot is guided along the slot in an edge direction of the dielectric substrate, and is radiated in an end-fire direction.

    [0003] Most end-fire antennas are traveling-wave antennas, and therefore, it is generally easy to achieve a wide band. For example, in Patent Document 1, the band of a slot antenna is widened by devising the shape of a feeder line. In addition, there has been known a technique for raising the gain of an end-fire antenna by an antenna having an array structure including a plurality of slots, or by a tapered slot antenna including a tapered slot having a tapered shape (See Patent Document 2).

    CITATION LIST


    PATENT DOCUMENT



    [0004] 

    Patent Document 1: Japanese Patent Laid-open Publication No. 2008-283251 ;

    Patent Document 2: Japanese Patent Laid-open Publication No. 2009-5086;

    Patent Document 3: U.S. Patent Application No. 2009/0195460;

    Patent Document 4: U.S. Patent Application No. 2009/0046019;

    Patent Document 5: U.S. Patent Application No. 2009/0207088; and

    Patent Document 6: U.S. Patent No. 6281843.



    [0005] WO 2005/036694 A2 discloses a vehicle tire interrogation system for interrogating sensors embedded in a vehicle tire. The interrogation system both transmits and receives appropriate RF signals to and from the sensors. The system includes antennas operating at two separate frequency bands that have an input impedance at both frequency bands at 50 ohms, are horizontally polarized, and have a gain at a minimum of 2 dBi at the two frequency bands. The antennas may be printed dual band antennas, such as wideband tapered slot antennas, dual band printed dipoles with reflectors or Yagi-Uda array antennas. The antennas can be embedded in various support structures to protect both the antenna and the vehicle tires.

    [0006] US 2009/0213024 A1 discloses a dipole antenna array, which includes a dielectric substrate; electric tuning elements mounted on a first surface and a second surface of the dielectric substrate; resonance elements and ground elements; and a feed line. Each resonance element includes first resonance parts, second resonance parts and a third resonance part. One of the second resonance parts connects the corresponding first resonance part to the third resonance part. The other second resonance parts respectively connect two neighboring first resonance parts. Each ground element includes first ground parts, second ground parts and a third ground part. One of the second ground parts connects one of the first ground parts to the third ground part. The other second ground parts respectively connect to two neighboring first ground parts.

    [0007] CA 2 596 025 discloses a double-sided PCB monopole Yagi-Uda antenna, preferably as part of a directional beam antenna comprising a plurality of such antennas vertically mounted in spoke-like fashion around a metallic antenna PCB substrate. The monopoles are printed on a monopole dielectric substrate. Each antenna comprises a driver, a reflector and a pair of directors, each forming a strip etched at corresponding positions on either side of the PCB and electrically connected at a distal end of the strip by a via passing through the PCB. The driver is connected to the central conductor of a connector, while the reflector and directors are grounded. Because the monopoles are printed on a double-sided PCB, there is no bias in the azimuth pattern of antenna when vertically mounted as contemplated above. The use of a monopole dielectric substrate provides generally more consistent and improved Performance over discrete wire monopole Yagi-Uda antennas.

    [0008] US 2008/0272976 A1 discloses an antenna device having a feeder electrode that extends linearly on a top surface of a dielectric substrate. A balanced electrode having two balanced transmission electrodes vertical to the extending direction of the feeder electrode and extending in parallel. The two balanced transmission electrodes are connected to the feeder electrode and separated by an interval of ½ of a wavelength of a transmission/reception signal. A radiation electrode having a first electrode connected to the one of the two balanced transmission electrodes and a second electrode connected to the other of the two balanced transmission electrodes and is positioned parallel to the feeder electrode. A waveguide electrode is formed at a Position separated from the radiation electrode by a predetermined interval and in parallel to the radiation electrode. A ground electrode is formed at an area of a back surface o f the dielectric substrate corresponding to an area including a portion where the feeder electrode is positioned. By connecting the two balanced electrodes to the feeder electrode at an interval of ½ of a wavelength in this manner, this branch portion has a signal branching function and a balun function at the same time.

    [0009] JPH07245525 represents additional prior art.

    SUMMARY OF INVENTION


    TECHNICAL PROBLEM



    [0010] However, when a slot antenna that radiates radio waves in an edge direction of a dielectric substrate is applied to radio waves in a very high frequency band such as a millimeter-wave band, the following two problems arise. First of all, there is such a problem that it is difficult to form a feed portion for feeding to a slot to be small according to the wavelength of radio waves in the millimeter-wave band, by a general etching process of a printed wiring substrate. In addition, there is such a problem that loss of a ground current flowing along the slot becomes relatively large. Since the loss of the ground current is directly associated with a reduction in radiation efficiency, this problem cannot be solved even by the above-described antenna having the array structure or the tapered slot antenna.

    [0011] It is an object of the present invention is to provide an antenna apparatus and a wireless communication apparatus including the antenna apparatus each capable of solving the above-described problems, each having a size smaller than that of the prior art, and having gain characteristics higher than that of the prior art.

    SOLUTION TO PROBLEM



    [0012] An antenna apparatus of the present invention is an antenna apparatus as defined in claim 1.

    [0013] In addition, in the antenna apparatus, each first parasitic element in one of the pair of adjacent first parasitic element arrays is opposed to a corresponding first parasitic element in another first parasitic element array at their respective adjacent ends.

    [0014] Further, in the above-described antenna apparatus, each first parasitic element in one of the pair of adjacent first parasitic element arrays is arranged so as to be shifted by a predetermined distance in a direction perpendicular to the longitudinal direction of the dipole antenna from a corresponding first parasitic element in another first parasitic element array.

    [0015] In one alternative of the invention, the above-described antenna apparatus further includes at least three second parasitic element arrays. Each of the second parasitic element arrays includes a plurality of second parasitic elements formed on the second surface of the dielectric substrate. In each of the second parasitic element arrays, each of the plurality of second parasitic elements has a strip shape substantially parallel to the longitudinal direction of the dipole antenna, and the plurality of second parasitic elements are arranged at predetermined third intervals so as to be electromagnetically coupled to each other. The at least three second parasitic element arrays are arranged substantially parallel to one another at predetermined fourth intervals so that each of second pseudo-slot openings is formed between each pair of adjacent second parasitic element arrays. The second pseudo-slot openings allowing the radio wave from the dipole antenna to propagate therethrough as magnetic currents. The dipole antenna further includes a third parasitic element formed on the second surface so as to be opposed to the first feed element, and a fourth parasitic element formed on the first surface so as to be opposed to the second feed element.

    [0016] In addition, in the above-described antenna apparatus, the third interval is set to substantially equal to or smaller than 1/8 of the wavelength.

    [0017] In another alternative of the invention, in the above-described antenna apparatus, an electrical length of the first feed element and an electrical length of the second feed element are preferably set to be different from each other.

    [0018] Still further, in the above-described antenna apparatus except for the above defined another alternative, an electrical length of the first feed element and an electrical length of the second feed element are set to be substantially equal to each other.

    [0019] In still another alternative of the invention, the above-described antenna apparatus further includes at least one parasitic element pair. Each of the at least one parasitic element pair includes two parasitic elements formed on at least one of the first and second surfaces and operates as a reflector. Each of the two parasitic elements has a strip shape and the two parasitic elements are formed in a straight line so as to be opposed to and be electromagnetically coupled to the dipole antenna. The straight line is parallel to the longitudinal direction of the dipole antenna and is located on an opposite side of the dipole antenna from the at least three first parasitic element arrays.

    [0020] A wirelss communication apparatus of the second inventionis a wireless communication apparatus including the above-described antenna apparatus.

    ADVANTAGEOUS EFFECTS OF INVENTION



    [0021] The antenna apparatus and wireless communication apparatus according to the present invention are configured to include at least three first parasitic element arrays each including a plurality of first parasitic elements formed on a first side of a dielectric substrate. In this case, in each of the first parasitic element arrays, each of the plurality of first parasitic elements has a strip shape substantially parallel to the longitudinal direction of the dipole antenna, and the plurality of first parasitic elements are arranged at the predetermined first intervals so as to be electromagnetically coupled to each other. The at least three first parasitic element arrays are arranged substantially parallel to one another at the predetermined second intervals so that the first pseudo-slot openings are formed between each pair of adjacent first parasitic element arrays. The first pseudo-slot openings allow the radio wave from the dipole antenna to propagate therethrough as the magnetic current. Therefore, it is possible to provide an antenna apparatus and a wireless communication apparatus each having a size smaller than that of the prior art and having gain characteristics higher than that of the prior art.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0022] 

    Fig. 1 is a top view of an antenna apparatus 100 according to a first embodiment;

    Fig. 2 is a reverse side view of the antenna apparatus 100 of Fig. 1;

    Fig. 3 is a top view of an antenna apparatus 100A according to a modified embodiment of the first embodiment;

    Fig. 4 is a reverse side view of the antenna apparatus 100A of Fig. 3;

    Fig. 5 is a top view of an antenna apparatus 100B of a second embodiment and according to the invention;

    Fig. 6 is a reverse side view of the antenna apparatus 100B of Fig. 5;

    Fig. 7 is a top view of an antenna apparatus 100C of a third embodiment and according to the invention;

    Fig. 8 is a reverse side view of the antenna apparatus 100C of Fig. 7;

    Fig. 9 is a top view of an antenna apparatus 100D of a fourth embodiment and according to the invention;

    Fig. 10 is a reverse side view of the antenna apparatus 100D of Fig. 9;

    Fig. 11 is a top view of an antenna apparatus 100E of a fith embodiment and according to the invention;

    Fig. 12 is a reverse side view of the antenna apparatus 100E of Fig. 11;

    Fig. 13 is a top view of a wireless communication apparatus 200 according to a sixth embodiment;

    Fig. 14 is a graph showing a radiation pattern on an XY-plane, when the number of parasitic element arrays 6 is set to 5 and the number of parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20 in the antenna apparatus 100 of Fig. 1;

    Fig. 15 is a graph showing a radiation pattern on the XY-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, and the length of a feed element 4b is set to be shorter than the length of a feed element 4a in the antenna apparatus 100 of Fig. 1;

    Fig. 16 is a graph showing a radiation pattern on an XZ-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, and the length of the feed element 4b is set to be shorter than the length of the feed element 4a in the antenna apparatus 100 of Fig. 1;

    Fig. 17 is a graph showing a radiation pattern on the XY-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and the parasitic element arrays 6 of the even-numbered rows are shifted by L5/2 in an X-axis direction in the antenna apparatus 100 of Fig. 1;

    Fig. 18 is a graph showing a radiation pattern on the XZ-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and the parasitic element arrays 6 of the even-numbered rows are shifted by L5/2 in the X-axis direction in the antenna apparatus 100 of Fig. 1;

    Fig. 19 is a graph showing a radiation pattern on the XY-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and parasitic elements 4c and 4d are added in the antenna apparatus 100 of Fig. 1;

    Fig. 20 is a graph showing a radiation pattern on the XZ-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and the parasitic elements 4c and 4d are added in the antenna apparatus 100 of Fig. 1;

    Fig. 21 is a graph showing a radiation pattern on the XY-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, the parasitic elements 4c and 4d are added, and parasitic element pairs 13 and 14 are added in the antenna apparatus 100 of Fig. 1;

    Fig. 22 is a graph showing a radiation pattern on the XZ-plane, when the number of the parasitic element arrays 6 is set to 5, the number of the parasitic elements 5 included in each of the parasitic element arrays 6 is set to 20, the length of the feed element 4b is set to be shorter than the length of the feed element 4a, the parasitic elements 4c and 4d are added, and the parasitic element pairs 13 and 14 are added in the antenna apparatus 100 of Fig. 1;

    Fig. 23 is a graph showing a relationship between an interval L5 between the parasitic elements 5 and the peak gain of a main beam, when an interval L6 between the parasitic element arrays 6 is set to λ/ 10 in the antenna apparatus 100E of Fig. 11; and

    Fig. 24 is a graph showing a relationship between the interval L6 between the parasitic element arrays 6 and the peak gain of a main beam, when the interval L5 between the parasitic elements 5 is set to λ/25 in the antenna apparatus 100E of Fig. 11.


    DESCRIPTION OF EMBODIMENTS



    [0023] Embodiments and embodiments of the present invention will be described hereinafter with reference to the drawings. In the embodiments, components similar to each other are denoted by the same reference numerals.

    FIRST EMBODIMENT



    [0024] Fig. 1 is a top view of an antenna apparatus 100 according to a first embodiment, and Fig. 2 is a reverse side view of the antenna apparatus 100 of Fig. 1. The antenna apparatus 100 according to the present embodiment is an end-fire antenna apparatus for a wireless communication apparatus that performs wireless communication in a high-frequency band such as a microwave band or a millimeter-wave band.

    [0025] Referring to Figs. 1 and 2, the antenna apparatus 100 is configured to include a dielectric substrate 1, ground conductors 10, 11 and 12, strip conductors 2, 30 and 31, and six parasitic element arrays 6 each including eight parasitic elements 5. It is noted that an XYZ coordinate system is defined as shown in Fig. 1 in the present embodiment, the following embodiments and modified embodiment. In this case, in Fig. 1, a right direction is referred to as an X-axis direction, and an upward direction is referred to as a Y-axis direction. In addition, a direction opposite to the X-axis direction is referred to as a -X-axis direction and a direction opposite to the Y-axis direction is referred to as a -Y-axis direction.

    [0026] Referring to Fig. 1, the dielectric substrate 1 is a glass epoxy substrate, for example. In addition, the ground conductors 10 and 11, the strip conductors 2 and 30, a feed element 4a, and the parasitic element arrays 6 are formed on a top surface of the dielectric substrate 1. On the other hand, the ground conductor 12, the strip conductor 31, and a feed element 4b are formed on a reverse surface of the dielectric substrate 1. In this case, the ground conductor 12 is formed at a left edge portion of the dielectric substrate 1 of Fig. 1. The strip conductor 2 is formed so as to oppose to the ground conductor 12, and to extend in the X-axis direction from the left edge of the dielectric substrate 1. The ground conductors 10 and 11 are formed on both sides of the strip conductor 2, respectively, so as to oppose to the ground conductor 12. There is a predetermined interval between the ground conductor 10 and the strip conductor 2, and there is a predetermined interval between the ground conductor 11 and the strip conductor 2. It is noted that the ground conductors 10, 11 and 12 are electrically connected to one another. Referring to Figs. 1 and 2, the ground conductors 10 and 11 and the strip conductor 2, and the ground conductor 12 sandwich the dielectric substrate 1 to configure a grounded coplanar line used as a feeder line 20.

    [0027] In addition, referring to Fig. 1, the strip conductor 30 has an electrical length L30, has one end connected to a right end of the strip conductor 2 of Fig. 1 and another end, and is formed so as to extend in the X-axis direction. Further, the feed element 4a has one end connected to another end of the strip conductor 30, and another end which is an open end. The feed element 4a extends in the Y-axis direction from another end of the strip conductor 30. Referring to Fig. 2, the strip conductor 31 has one end connected to the ground conductor 2 and another end connected to one end of the feed element 4b. The strip conductor 31 is formed so as to oppose to the strip conductor 30. In addition, the feed element 4b has the one end connected to another end of the strip conductor 31 and another end which is an open end. The feed element 4b extends in the -Y-axis direction from another end of the strip conductor 30. The feed elements 4a and 4b formed as described above operate as a half-wave printed dipole antenna (referred to as a dipole antenna hereinafter) 4 having an electrical length L4 from the open end of the feed element 4a to the open end of the feed element 4b, and radiate radio waves mainly in the X-axis direction. The X-axis direction is also referred to as an end-fire direction hereinafter.

    [0028] Referring to Fig. 1, each of the parasitic element arrays 6 is configured to include the eight parasitic elements 5 formed on the top surface of the dielectric substrate 1. In this case, each of the parasitic elements 5 has a strip shape extending substantially parallel to a longitudinal direction (Y-axis direction) of the dipole antenna 4. Further, in each of the parasitic element arrays 6, the parasitic elements 5 are arranged at predetermined intervals L5 in a straight line parallel to the X-axis, so as to be electromagnetically coupled to each other.

    [0029] In addition, referring to Fig. 1, the six parasitic element arrays 6 are formed substantially parallel to one another so that a pair of parasitic element arrays 6 adjacent to each other in the Y-axis direction form a pseudo-slot opening S6 having a predetermined width L6. In the case of Fig. 1, five pseudo-slot openings S6 extending in the X-axis direction are formed by the six parasitic element arrays 6. It is noted that each parasitic element 5 in one of a pair of parasitic element arrays 6 adjacent to each other in the Y-axis direction faces a corresponding parasitic element 5 in another parasitic element array 6 so that the parasitic elements 5 have an interval L6 therebetween at their respective adjacent ends. Therefore, six corresponding parasitic elements in the six parasitic element arrays 6 are arranged in a straight line parallel to the Y-axis.

    [0030] In this case, the electrical length L4 of the dipole antenna 4 is set to be substantially equal to 1/2 of the wavelength λ of a high-frequency signal to be fed to the feeder line 20. Therefore, it is possible to radiate radio waves from the dipole antenna 4 efficiently. In addition, the electrical lengths of the respective feed elements 4a and 4b are set to be substantially equal to each other. Further, the interval L5 is set to, for example, equal to or smaller than λ/8 so that adjacent parasitic elements 5 are electromagnetically coupled to each other. Still further, the width L6 (interval L6) is set to λ/10, for example. Further, an interval L45 between those parasitic elements 5 closest to the dipole antenna 4 and the dipole antenna 4 is set so that the parasitic elements 5 closest to the dipole antenna 4 and the dipole antenna 4 are electromagnetically coupled to each other, and is preferably set to a value equal to the interval L5. The electrical length L30 is set to be equal to the interval L5 for example.

    [0031] Referring to Figs. 1 and 2, a high-frequency signal from a high-frequency circuit that outputs a high-frequency signal having frequency components in the high-frequency band such as the microwave band or the millimeter-wave band is transmitted via the feeder line 20 and a transmission line composed of the strip conductors 30 and 31 which are provided to sandwich the dielectric substrate 1, and is fed to the dipole antenna 4 so as to be radiated in the end-fire direction from the dipole antenna 4. On the other hand, in each of the parasitic element arrays 6, the parasitic elements 5 adjacent to each other in the X-axis direction are electromagnetically coupled to each other in the X-axis direction, and each of the parasitic element arrays 6 operates as an electric wall extending in the X-axis direction. Then, the pseudo-slot opening S6 is formed between a pair of the parasitic element arrays 6 adjacent to each other in the Y-axis direction. Therefore, an electric field parallel to the Y-axis direction is generated in each of the pseudo-slot openings S6, and a magnetic current parallel to the X-axis direction flows through each of the pseudo-slot openings S6 accordingly. Therefore, the radio waves radiated from the dipole antenna 4 are transmitted through the top surface of the dielectric substrate 1 along the pseudo-slot openings S6 between the parasitic element arrays 6 so as to be guided in the X-axis direction, and are radiated in the end-fire direction from an edge portion 1a (See Fig. 1) on the right side of the dielectric substrate 1. Namely, the antenna apparatus 100 operates with the pseudo-slot openings S6 serving as magnetic current sources. In this case, the radio waves are aligned in phase at the edge portion 1a of the dielectric substrate 1, and an equiphase wave plane is generated at the end portion 1a. It is noted that each parasitic element 5 in one of a pair of parasitic element arrays 6 adjacent to each other in the Y-axis direction and a corresponding parasitic element 5 in another parasitic element array 6 are not electromagnetically coupled to each other in the Y-axis direction, and thus do not resonate.

    [0032] As described above, the antenna apparatus 100 is configured to include the dielectric substrate 1, the dipole antenna 4, and the six parasitic element arrays 6. The dipole antenna 4 includes the feed element 4a, which is formed on the top surface of the dielectric substrate 1 and is connected to the feeder line 20, and the feed element 4b, which is formed on the reverse surface of the dielectric substrate 1 and is connected to the ground conductor 12. The dipole antenna 4 has the electrical length of substantially 1/2 of the wavelength λ of the high-frequency signal to be radiated. Each of the six parasitic element arrays 6 includes the plurality of parasitic elements 5 formed on the top surface of the dielectric substrate 1. In this case, the antenna apparatus 100 is characterized in that, in each of the parasitic element arrays 6, the plurality of parasitic elements 5 have a strip shape substantially parallel to the longitudinal direction of the dipole antenna 4 and are arranged at the predetermined intervals L5 so as to be electromagnetically coupled to each other, and the six parasitic element arrays 6 are arranged substantially parallel to one another at the predetermined intervals L6 so that the pseudo-slot opening S6 that allows the radio wave from the dipole antenna 4 to propagate therethrough as the magnetic current is formed between each pair of adjacent parasitic element arrays 6.

    [0033] Therefore, according to the antenna apparatus 100 of the present embodiment, each of the parasitic element arrays 6 operates as an electric wall, and the pseudo-slot opening S6 is formed between two parasitic element arrays 6 adjacent to each other in the Y-axis direction. Namely, since the antenna apparatus 100 has such a configuration in which, for example, a conductor extending in the X-axis direction is cut into the plurality of parasitic elements 5, the length of the conductor is reduced, and this leads to reduced currents flowing along the pseudo-slot openings S6.

    [0034] In addition, by setting the interval L5 as small as possible, the parasitic elements 5 adjacent to each other in the X-axis direction are intensely electromagnetically coupled to each other via a free space on the top surface of the dielectric substrate 1, and the density of the lines of electric force in the dielectric substrate 1 can be decreased. Therefore, the influence of the dielectric loss in the dielectric substrate 1 can be reduced. Therefore, it is possible to obtain a gain characteristic higher than that of the prior art.

    [0035] Further, according to the antenna apparatus 100 of the present embodiment, by forming the parasitic elements 5 to be smaller in size, it is possible to reduce currents generated in the parasitic elements 5. In addition, by narrowing the interval L5 between the parasitic elements 5, the dielectric loss in the dielectric substrate 1 can be reduced. Therefore, it is possible to miniaturize the antenna apparatus 100, and to obtain high gain characteristics.

    [0036] In addition, since equiphase wave plane is generated at the end portion 1a of the dielectric substrate 1, a beam width in a vertical plane and a beam width in a horizontal plane can be narrowed than those of the prior art.

    [0037] Further, since the antenna apparatus 100 operates using the magnetic currents flowing through the pseudo-slot openings S6, the influence of interference between the antenna apparatus 100 and conductors arranged near the antenna apparatus 100, on the gain is relatively small.

    [0038] Still further, according to the present embodiment, since the feeder line 20 is a grounded coplanar line, the ground conductors 10 and 11 operate as reflectors that reflect radio waves radiated in the -X-axis direction from the dipole antenna 4, in the X-axis direction. Therefore, radio waves from the dipole antenna 4 can be efficiently directed to the parasitic element arrays 6, and this leads to increased gain.

    [0039] Therefore, the antenna apparatus 100 according to the present embodiment can increase the power efficiency of a wireless communication apparatus that performs communication in the high-frequency band such as the millimeter-wave band, within which a relatively large propagation loss in space occurs.

    [0040] In addition, since the antenna apparatus 100 according to the present embodiment includes the dipole antenna 4, it is relatively easy to realize an antenna apparatus for transmitting and receiving high-frequency signals in a millimeter-wave band, etc.

    [0041] In the present embodiment, the antenna apparatus 100 includes the six parasitic element arrays 6, however, the present invention is not limited this. The antenna apparatus 100 may include three or more parasitic element arrays 6 arranged so as to form a plurality of pseudo-slot openings S6. It is noted that the longer the length in the end-fire direction of each parasitic element array 6 (the larger the number of parasitic elements 5) becomes, the narrower the beam width in the vertical plane (XZ-plane) becomes. In addition, the larger the number of parasitic element arrays 6 becomes, the narrower the beam width in the horizontal plane (XY-plane) becomes. Namely, the beam widths in the vertical and horizontal planes can be controlled independently by the length and number of the parasitic element arrays 6.

    MODIFIED EMBODIMENT OF THE FIRST EMBODIMENT



    [0042] In the first embodiment, the lengths in the X-axis direction of the respective parasitic element arrays 6 (i.e., the numbers of parasitic elements 5 in the respective parasitic element arrays 6) are the same, however, the present invention is not limited this. The lengths in the X-axis direction of the respective parasitic element arrays 6 may be different from one another. In addition, in the first embodiment, in each of the parasitic element arrays 6, the parasitic elements 5 are arranged at equal intervals L5, however, the first embodiment is not limited to this. In each of the parasitic element arrays 6, the parasitic elements 5 may be arranged at unequal intervals so as to be electromagnetically coupled to each other in the X-axis direction. However, it is noted that the maximum value of the intervals between the parasitic elements 5 in each of the parasitic element arrays 6 is preferably equal to or smaller than λ/8.

    [0043] Fig. 3 is a top view of an antenna apparatus 100A according to a modified embodiment of the first embodiment, and Fig. 4 is a reverse side view of the antenna apparatus 100A of Fig. 3. The antenna apparatus 100A is different from the antenna apparatus 100 in that the antenna apparatus 100A includes parasitic element arrays 61 to 67 instead of the six parasitic element arrays 6. In the present modified embodiment, only differences from the first embodiment will be described.

    [0044] Referring to Fig. 3, the parasitic element arrays 61, 62, 63, 64, 65, 66 and 67 are configured to include 9, 8, 8, 7, 8, 8 and 9 parasitic elements 5, respectively. In each of the parasitic element arrays 61 to 67, the parasitic elements 5 are formed and arranged in a manner similar to that of the parasitic elements 5 in the parasitic element arrays 6 according to the first embodiment. In addition, in Fig. 3, the parasitic element arrays 61, 62, 63, 64, 65, 66 and 67 are formed substantially parallel to one another so that a pair of parasitic element arrays adjacent to each other in the Y-axis direction form a pseudo-slot opening S60 having a predetermined width L60. In the case of Fig. 3, six pseudo-slot openings S60 extending in the X-axis direction are formed by the seven parasitic element arrays 61 to 67.

    [0045] It is noted that, in the parasitic element arrays 61 to 67, each parasitic element 5 in one of a pair of parasitic element arrays adjacent to each other in the Y-axis direction is arranged so as to be shifted by a predetermined distance D in a direction perpendicular to the longitudinal direction of the dipole antenna 4 from a corresponding parasitic element 5 in another parasitic element array. Further, referring to Fig. 3, the interval L5, the interval L45 and the width L60 are set in the same manners as those of the interval L5, the interval L45 and the width L6 in the first embodiment, respectively.

    [0046] Referring to Figs. 3 and 4, the radio waves radiated from the dipole antenna 4 are transmitted through the top surface of the dielectric substrate 1 along the respective pseudo-slot openings S60 between the parasitic element arrays 61 to 67 so as to be guided in the X-axis direction, and are radiated in the end-fire direction from the edge portion 1a on the right side of the dielectric substrate 1. The antenna apparatus 100A exhibits advantageous effects the same as those of the antenna apparatus 100 according to the first embodiment.

    SECOND EMBODIMENT



    [0047] Fig. 5 is a top view of an antenna apparatus 100B according to a second embodiment and according to the present invention, and Fig. 6 is a reverse side view of the antenna apparatus 100B of Fig. 5. As compared with the antenna apparatus 100 according to the first embodiment, the antenna apparatus 100B according to the present embodiment is characterized by including a dipole antenna 4A instead of the dipole antenna 4, and further including six parasitic element arrays 8 each including eight parasitic elements 7. In the present embodiment, only differences from the first embodiment will be described.

    [0048] Referring to Figs. 5 and 6, the dipole antenna 4A is configured to include the feed elements 4a and 4b, and parasitic elements 4c and 4d. In this case, the parasitic element 4c is formed on the top surface of the dielectric substrate 1 so as to oppose to the feed element 4b, and to have a predetermined interval with the feed element 4a. In addition, the parasitic element 4d is formed on the reverse surface of the dielectric substrate 1 so as to oppose to the feed element 4a and to have a predetermined interval with the feed element 4b.

    [0049] In addition, referring to Fig. 6, each of the parasitic element arrays 8 is configured to include the eight parasitic elements 7 formed on the reverse surface of the dielectric substrate 1. In this case, the parasitic elements 7 have a strip shape extending substantially parallel to a longitudinal direction (Y-axis direction) of the dipole antenna 4A. Further, in each of the parasitic element arrays 8, the parasitic elements 7 are arranged at predetermined intervals L7 and in a straight line parallel to the X-axis, so as to be electromagnetically coupled to each other.

    [0050] In addition, referring to Fig. 6, the six parasitic element arrays 8 are formed substantially parallel to one another so that a pair of parasitic element arrays 8 adjacent to each other in the Y-axis direction form a pseudo-slot opening S8 having a predetermined width L8. In the case of Fig. 6, five pseudo-slot openings S8 extending in the X-axis direction are formed by the six parasitic element arrays 8. It is noted that parasitic element 7 in one of a pair of parasitic element arrays 8 adjacent to each other in the Y-axis direction faces a corresponding parasitic element 7 in another parasitic element array 8 so that the parasitic elements 7 have an interval L8 therebetween at their respective adjacent ends.

    [0051] It is noted that, in the present embodiment, the interval L7 is set to be equal to the interval L5, the width L8 is set to be equal to the width L6, and the parasitic elements 7 are formed so as to oppose to parasitic elements 5, respectively.

    [0052] In each of the parasitic element arrays 8, the parasitic elements 7 adjacent to each other in the X-axis direction are electromagnetically coupled to each other in the X-axis direction, and each of the parasitic element arrays 8 operates as an electric wall extending in the X-axis direction. Then, a pseudo-slot opening S8 is formed between a pair of the parasitic element arrays 8 adjacent to each other in the Y-axis direction. Therefore, an electric field parallel to the Y-axis direction is generated in each of the pseudo-slot openings S8, and a magnetic current parallel to the X-axis direction flows through each of the pseudo-slot openings S8 accordingly. Therefore, the radio waves radiated from the dipole antenna 4A are transmitted through the reverse surface of the dielectric substrate 1 along the pseudo-slot openings S8 between the parasitic element arrays 8 so as to be guided in the X-axis direction, and are radiated in the end-fire direction from the edge portion 1a on the right side of the dielectric substrate 1. Namely, the antenna apparatus 100B operates with the pseudo-slot openings S8 serving as magnetic current sources. In this case, the radio waves are aligned in phase at the edge portion 1a of the dielectric substrate 1, and an equiphase wave plane is generated at the end portion 1a. It is noted that each parasitic element 7 in one of a pair of parasitic element arrays 8 adjacent to each other in the Y-axis direction and a corresponding parasitic element 7 in another parasitic element array 8 are not electromagnetically coupled to each other in the Y-axis direction, and thus do not resonate.

    [0053] As described above, referring to Figs. 5 and 6, the radio waves radiated from the dipole antenna 4A propagate through the top surface of the dielectric substrate 1 along the pseudo-slot openings S6 as magnetic currents, propagate through the reverse surface of the dielectric substrate 1 along the pseudo-slot openings S8 as magnetic currents, and are radiated in the end-fire direction from the edge portion 1a of the dielectric substrate 1.

    [0054] According to the dipole antenna 4A of the present embodiment, since the parasitic element 4c is electromagnetically coupled to the feed element 4b, and the parasitic element 4d is electromagnetically coupled to the feed element 4a, the dipole antenna 4A can radiate radio waves more efficiently than the above-described dipole antenna 4. Further, since the antenna apparatus 100B further includes the parasitic element arrays 8, radiation efficiency and opening efficiency can be increased than those of the above-described embodiment and modified embodiment.

    [0055] The interval L7 is set to be equal to the interval L5 and the width L8 is set to be equal to the width L6 in the present embodiment, however, the present invention is not limited to this. In addition, the interval L7 does not need to be equal to the interval L5 but is preferably equal to or smaller than λ/8. In addition, the width L8 does not need to be equal to the width L6 but is set to λ/10, for example. Further, the arrangement of the parasitic element arrays 6 on the top surface of the dielectric substrate 1 and the arrangement of the parasitic element arrays 8 on the reverse surface do not need to be identical.

    [0056] In addition, the antenna apparatus 100B includes the parasitic element arrays 6 and 8 in the present embodiment, however, the present invention is not limited to this. The antenna apparatus 100B may include only either the parasitic element arrays 6 or 8.

    THIRD EMBODIMENT



    [0057] Fig. 7 is a top view of an antenna apparatus 100C according to a third embodiment and according to the present invention, and Fig. 8 is a reverse side view of the antenna apparatus 100C of Fig. 7. As compared with the antenna apparatus 100B according to the second embodiment, the antenna apparatus 100C according to the present embodiment is configured to further include a parasitic element pair 13 including parasitic elements 13a and 13b, and a parasitic element pair 14 including parasitic elements 14a and 14b. In the present embodiment, only differences from the second embodiment will be described.

    [0058] Referring to Figs. 7 and 8, the parasitic elements 13a and 13b have a strip shape and are formed on the top surface of the dielectric substrate 1. The parasitic elements 13a and 13b are formed in a straight line parallel to the longitudinal direction of the dipole antenna 4A, and are located on the opposite side of the dipole antenna 4A from parasitic element arrays 6, respectively. The parasitic elements 13a and 13b are formed so as to oppose to the dipole antenna 4A and to be electromagnetically coupled to the dipole antenna 4A, and operate as reflectors. In addition, the parasitic elements 14a and 14b have a strip shape and are formed on the reverse surface of the dielectric substrate 1. The parasitic elements 14a and 14b are formed in a straight line parallel to the longitudinal direction of the dipole antenna 4A, and are located on the opposite side of the dipole antenna 4A from parasitic element arrays 8, respectively. The parasitic elements 14a and 14b are formed so as to oppose to the dipole antenna 4A and to be electromagnetically coupled to the dipole antenna 4A, and operate as reflectors.

    [0059] In addition, referring to Fig. 7, the parasitic element 13a is formed in a region of the top surface of the dielectric substrate 1 between the feed element 4a and the ground conductor 11, so as to extend in the Y-axis direction. In addition, the parasitic element 13b is formed in a region of the top surface of the dielectric substrate 1 between the parasitic element 4c and the ground conductor 10, so as to extend in the Y-axis direction. Further, the parasitic elements 14a and 14b are formed on the reverse surface of the dielectric substrate 1 so as to oppose to the parasitic elements 13a and 13b, respectively. The parasitic element 13a is electromagnetically coupled to the feed element 4a, the parasitic element 13b is electromagnetically coupled to the parasitic element 4c, the parasitic element 14a is electromagnetically coupled to a parasitic element 4d, and the parasitic element 14b is electromagnetically coupled to a feed element 4b.

    [0060] According to the present embodiment, since the parasitic element pairs 13 and 14 which operate as reflectors are provided at locations on the opposite side of the dipole antenna 4A from a radiation direction of radio waves from the dipole antenna 4A, the radio waves radiated from the dipole antenna 4A can be directed in the end-fire direction more efficiently than the second embodiment. Therefore, it is possible to improve the FB (Front to Back) ratio than that of the second embodiment. In particular, the advantageous effects provided by the parasitic element pairs 13 and 14 become large, when the size in the Y-axis direction of the antenna apparatus 100C increases due to an increase in the numbers of the parasitic element arrays 6 and 8. In addition, the advantageous effects provided by the parasitic element pairs 13 and 14 become large, when the feeder line 20 is a feeder line such as a microstrip line, which does not include the ground conductors 10 and 11 operating as reflectors.

    [0061] It is noted that the antenna apparatus 100C includes two parasitic element pairs 13 and 14 in the present embodiment, however, the present invention is not limited to this. The antenna apparatus 100C may include only one of the parasitic element pairs 13 or 14.

    [0062] In addition, the antenna apparatus 100C includes the parasitic element arrays 6 and 8 in the present embodiment, however, the present invention is not limited to this. The antenna apparatus 100C may include only either the parasitic element arrays 6 or 8.

    FOURTH EMBODIMENT



    [0063] Fig. 9 is a top view of an antenna apparatus 100D according to a fourth embodiment and according to the present invention and Fig. 10 is a reverse side view of the antenna apparatus 100D of Fig. 9. As compared with the antenna apparatus 100A according to the modified embodiment of the first embodiment, the antenna apparatus 100D according to the present embodiment is characterized by including a feed element 4e instead of the feed element 4b. In the present embodiment, only differences from the modified embodiment of the first embodiment will be described. In the above-described embodiments and modified embodiment, the each electrical lengths of feed elements 4a and 4b are set to equal values. On the other hand, the electrical length of the feed element 4e is set to be shorter than the electrical length of the feed element 4b in the present embodiment. In addition, the feed elements 4a and 4e operate as a dipole antenna 4B having an electrical length L4 from the open end of the feed element 4a to an open end of the feed element 4e.

    [0064] In the present embodiment and the above-described embodiments, since the feeder line 20 is an unbalanced transmission line, if the balanced dipole antenna 4 is connected to the feeder line 20, then a current flowing through the feed element 4a and a current flowing through the feed element 4b become unbalanced. As a result, a beam in a horizontal plane may not be directed in an end-fire direction. Since each of the antenna apparatuses 100, 100A, 100B, and 100C according to the above-described embodiments and modified embodiment has a beam width smaller than that of the prior art, unless the direction of the beam is directed to the front (which is the end-fire direction) of the antenna apparatuses 100, 100A, 100B, and 100C, user usability becomes poor.

    [0065] According to the antenna apparatus 100D of the present embodiment, by setting the electrical length of the feed element 4e to be shorter than the electrical length of the feed element 4a, the above-described unbalanced currents are adjusted, enabling to direct the beam in the end-fire direction. In addition, since the radiation direction of the radio waves from the dipole antenna 4B is directed in the end-fire direction, the wave guide efficiency of parasitic element arrays 61 to 67 is improved than those of the above-described embodiments and modified embodiment.

    [0066] The electrical length of the feed element 4e is set to be shorter than the electrical length of the feed element 4a, however, the present invention is not limited to this. The electrical length of the feed element 4a and the electrical length of the feed element 4e are set to be different from each other so that the radiation direction of the radio waves from the dipole antenna 4B is directed in a desired direction such as the end-fire direction.

    [0067] In addition, parasitic element arrays are not provided on the reverse surface of the dielectric substrate 1 in the present embodiment, however, the present invention is not limited to this. For example, at least three parasitic element arrays similar to the parasitic element arrays 61 to 67 may be provided on the reverse surface of the dielectric substrate 1. In this case, in each parasitic element array, a plurality of parasitic elements (e.g., the parasitic elements 7 of Fig. 8) have a strip shape substantially parallel to a longitudinal direction of the dipole antenna 4B, and are arranged at predetermined intervals so as to be electromagnetically coupled to each other. In addition, the at least three parasitic element arrays are arranged substantially parallel to one another at predetermined intervals so that a pseudo-slot opening (e.g., the pseudo-slot opening S8 of Fig. 8) that allows the radio wave from the dipole antenna 4B to propagate therethrough as a magnetic current is formed between each pair of adjacent parasitic element arrays.

    FIFTH EMBODIMENT



    [0068] Fig. 11 is a top view of an antenna apparatus 100E according to a fifth embodiment and according to the present invention and Fig. 12 is a reverse side view of the antenna apparatus 100E of Fig. 11. As compared with the antenna apparatus 100C according to the third embodiment, the antenna apparatus 100E according to the present embodiment is characterized by including the feed element 4e instead of the feed element 4b. In the present embodiment, only differences from the third embodiment will be described.

    [0069] In the present embodiment, the electrical length of the feed element 4e is set to be shorter than the electrical length of the feed element 4b, in a manner the same as that of the antenna apparatus 100D according to the fourth embodiment. In addition, the feed elements 4a, 4c, 4d, and 4e operate as a dipole antenna 4C having an electrical length L4 from the open end of the feed element 4a to the open end of the feed element 4e.

    [0070] According to the present embodiment, by setting the electrical length of the feed element 4e to be shorter than the electrical length of the feed element 4a in a manner similar to that of the fourth embodiment, the beam can be directed in the end-fire direction. In addition, since a radiation direction of radio waves from the dipole antenna 4C is directed in the end-fire direction, the wave guide efficiency of parasitic element arrays 6 and 8 is improved than that of the third embodiment.

    [0071] The electrical length of the feed element 4e is set to be shorter than the electrical length of the feed element 4a, however, the present invention is not limited to this. The electrical length of the feed element 4a and the electrical length of the feed element 4e are set to be different from each other so that the radiation direction of radio waves from the dipole antenna 4C is directed in a desired direction such as the end-fire direction.

    [0072] In addition, the electrical length of the parasitic element 4c is set to be longer than the electrical length of the feed element 4e in the present embodiment, however, the present invention is not limited to this. The electrical length of the parasitic element 4c may be set to be substantially equal to the electrical length of the feed element 4e.

    [0073] Further, the antenna apparatus 100E includes the parasitic element arrays 6 and 8 in the present embodiment, however, the present invention is not limited to this. The antenna apparatus 100E may include only either the parasitic element arrays 6 or 8. Still further, the antenna apparatus 100E includes parasitic element pairs 13 and 14, however, the present invention is not limited to this. The antenna apparatus 100E may include only one of the parasitic element pairs 13 or 14.

    SIXTH EMBODIMENT



    [0074] Fig. 13 is a top view of a wireless communication apparatus 200 according to a sixth embodiment. Referring to Fig. 13, the wireless communication apparatus 200 is a wireless communication apparatus such as a wireless module substrate, and is configured to include the antenna apparatus 100 according to the first embodiment, a higher-layer circuit 501, a baseband circuit 502, and a high-frequency circuit 503. In this case, the higher-layer circuit 501, the baseband circuit 502, and the high-frequency circuit 503 are provided on the top surface of the dielectric substrate 1. It is noted that the respective circuits 501 to 503 are provided in the -X-axis direction with respect to the dipole antenna 4.

    [0075] Referring to Fig. 13, the higher layer circuit 501 is a circuit of a layer higher than the MAC (Media Access Control) layer and the physical layers of an application layer and the like, and includes a communication circuit and a host processing circuit, for example. The higher layer circuit 501 outputs a predetermined data signal to the baseband circuit 502, and executes predetermined signal processing for a baseband signal from the baseband circuit 502 so as to convert the baseband signal into a data signal. In addition, the baseband circuit 502 executes a waveform shaping process for the data signal from the higher layer circuit 501, and thereafter, modulates a predetermined carrier signal according to the processed data signal and outputs the resultant signal to the high-frequency circuit 503. Further, the baseband circuit 502 demodulates the high-frequency signal from the high-frequency circuit 503 into the baseband signal, and outputs the baseband signal to the higher layer circuit 501.

    [0076] In addition, referring to Fig. 13, the high-frequency circuit 503 executes a power amplification process and a waveform shaping process for the high-frequency signal from the baseband circuit 502 in the radio-frequency band, and outputs the resultant signal to the dipole antenna 4 via the feeder line 2. Further, the high-frequency circuit 503 executes predetermined processing of frequency conversion and the like for the high-frequency signal wirelessly received by the dipole antenna 4B, and thereafter, outputs the resultant signal to the baseband circuit 502.

    [0077] The high-frequency circuit 503 and the antenna apparatus 100 are connected to each other via a high-frequency transmission line. In addition, an impedance matching circuit is provided between the high-frequency circuit 503 and the antenna apparatus 100 when needed. The wireless communication apparatus 200 configured as described above wirelessly transmits and receives the high-frequency signal by using the antenna apparatus 100, and therefore, it is possible to realize a wireless communication apparatus having a size smaller than that of the prior art and a gain higher than that of the prior art.

    [0078] The wireless communication apparatus 200 according to the present embodiment includes the antenna apparatus 100. The wireless communication apparatus 200 may include the antenna apparatus 100A, 100B, 100C, 100D or 100E.

    [0079] In addition, the wireless communication apparatus 200 according to the present embodiment performs wireless transmission and reception, however, the present invention is not limited to this. The wireless communication apparatus 200 may perform only wireless transmission or only wireless reception.

    IMPLEMENTATION EXAMPLES



    [0080] With reference to Figs. 14 to 22, results obtained by performing three-dimensional electromagnetic field analysis on the antenna apparatus 100 of Fig. 1 will be described. It is noted that the number of parasitic element arrays 6 is set to 5, and the number of parasitic elements 5 included in each parasitic element array 6 is set to 20 in Figs. 14 to 22. Further, the thickness of the dielectric substrate 1 is set to 0.2 mm and the frequency of a high-frequency signal to be fed to the dipole antenna 4 is set to 60 GHz.

    [0081] Fig. 14 is a graph showing a radiation pattern on the XY-plane of the antenna apparatus 100 of Fig. 1. As shown in Fig. 14, it can be seen that a relatively narrow beam width can be obtained in the XY-plane. In addition, Figs. 15 and 16 are graphs showing radiation patterns on the XY-plane and the XZ-plane, respectively, when the length of the feed element 4b is set to be shorter than the length of the feed element 4a in the antenna apparatus 100 of Fig. 1. As shown in Figs. 15 and 16, it can be seen that by setting the length of the feed element 4b to be shorter than the length of the feed element 4a, the beam direction is directed in the X-axis direction (end-fire direction) without any change in beam width.

    [0082] Figs. 17 and 18 are graphs showing radiation patterns on the XY-plane and the XZ-plane, respectively, when the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and the parasitic element arrays 6 of the even-numbered rows are shifted by L5/2 in the X-axis direction in the antenna apparatus 100 of Fig. 1. Comparing Figs. 17 and 18 with Figs. 15 and 16, it can be seen that even if the arrangement of the parasitic element arrays 6 is changed, the radiation characteristics do not substantially change.

    [0083] Figs. 19 and 20 are graphs showing radiation patterns on the XY-plane and the XZ-plane, respectively, when the length of the feed element 4b is set to be shorter than the length of the feed element 4a, and parasitic elements 4c and 4d (See Figs. 5 and 6, for example) are added in the antenna apparatus 100 of Fig. 1. Comparing Figs. 19 and 20 with Figs. 15 and 16, it can be seen that by adding the parasitic elements 4c and 4d, the gain increases substantially without any change in the shapes of the radiation patterns.

    [0084] Figs. 21 and 22 are graphs showing radiation patterns on the XY-plane and the XZ-plane, respectively, when the length of the feed element 4b is set to be shorter than the length of the feed element 4a, parasitic elements 4c and 4d are added, and parasitic element pairs 13 and 14 (See Figs. 7 and 8, for example) are added in the antenna apparatus 100 of Fig. 1. Comparing Figs. 21 and 22 with Figs. 15 to 18, it can be seen that by adding the parasitic element pairs 13 and 14, the gain increases substantially without any change in the shapes of the radiation patterns.

    [0085] Next, with reference to Figs. 23 and 24, there will be described results of study of optimal values for the interval L5 between the feed elements 5 and the interval L6 between the parasitic element arrays 6 in the antenna apparatus 100E of Fig. 11. It is noted that the frequency of the high-frequency signal to be fed to the dipole antenna 4C is set to 62 GHz. In addition, the length of the feed element 4e is set to be shorter than the length of the feed element 4a so as to direct radio waves from the dipole antenna 4C in the end-fire direction. Further, the width in the X-axis direction of the parasitic elements 5 is set to λ/25 and the length in the Y-axis direction of the parasitic elements 5 is set to about three times the width in the X-axis direction of the parasitic elements 5.

    [0086] Fig. 23 is a graph showing a relationship between the interval L5 between the parasitic elements 5 and the peak gain of a main beam, when the interval L6 between the parasitic element arrays 6 is set to λ/10 in the antenna apparatus 100E of Fig. 11. As shown in Fig. 23, the smaller the interval L5 becomes, the higher the peak gain becomes. In particular, by setting the interval L5 to equal to or smaller than 8/λ, a high peak gain of equal to or larger than 9.5 dBi can be obtained. In addition, Fig. 24 is a graph showing a relationship between the interval L6 between the parasitic element arrays 6 and the peak gain of a main beam, when the interval L5 between the parasitic elements 5 is set to λ/25 in the antenna apparatus 100E of Fig. 11. As shown in Fig. 24, the smaller the interval L6 becomes, the higher the peak gain becomes. In particular, by setting the interval L6 to equal to or smaller than 0.4 λ, a high peak gain of equal to or larger than 9.5 dBi can be obtained.

    [0087] The parasitic element arrays 6, 61 to 67, and 8 are arranged at equal intervals in the above-described embodiments and modified embodiment, however, the present invention is not limited to this. The parasitic element arrays 6, 61 to 67 and 8 may be arranged at unequal intervals. It is noted, however, that the maximum value of the intervals between a plurality of parasitic elements is preferably equal to or smaller than 0.4 λ. In addition, the parasitic element arrays 6, 61 to 67 and 8 are arranged linearly in the above-described embodiments and modified embodiment, however, the present invention is not limited to this. Each of the parasitic element arrays 6, 61 to 67 and 8 may be arranged along a curve. Further, in each of the parasitic element arrays 6, 61 to 67 and 8 in the above-described embodiments and modified embodiment, the parasitic elements 5 and 7 are arranged at equal intervals, however, the present invention is not limited to this. The parasitic elements 5 and 7 may be arranged at unequal intervals. It is noted, however, that the maximum value of the intervals between the parasitic elements 5 and 7 in each of the parasitic element arrays 6, 61 to 67 and 8 is preferably equal to or smaller than λ/8.

    [0088] In addition, a grounded coplanar line is used as the feeder line 20 for transmitting high-frequency signals in the above-described embodiments and modified embodiment, however, the present invention is not limited to this. An unbalanced transmission line or balanced transmission line such as a microstrip line may be used as the feeder line 20.

    INDUSTRIAL APPLICABILITY



    [0089] As described above in detail, the antenna apparatus and wireless communication apparatus according to the present invention are inter alia configured to include at least three first parasitic element arrays each including a plurality of first parasitic elements formed on a first side of a dielectric substrate. In this case, in each of the first parasitic element arrays, each of the plurality of first parasitic elements has a strip shape substantially parallel to the longitudinal direction of the dipole antenna, and the plurality of first parasitic elements are arranged at the predetermined first intervals so as to be electromagnetically coupled to each other. The at least three first parasitic element arrays are arranged substantially parallel to one another at the predetermined second intervals so that the first pseudo-slot openings are formed between each pair of adjacent first parasitic element arrays. The first pseudo-slot openings allow the radio wave from the dipole antenna to propagate therethrough as the magnetic current. Therefore, it is possible to provide an antenna apparatus and a wireless communication apparatus each having a size smaller than that of the prior art and having gain characteristics higher than that of the prior art.

    [0090] The antenna apparatuses and wireless communication apparatus according to the present invention are useful as antenna apparatuses and a wireless communication apparatus for the field of high-frequency communication, etc.

    REFERENCE SIGNS LIST



    [0091] 
    1
    dielectric substrate,
    2, 30 and 31
    strip conductor,
    4, 4A, 4B and 4C
    dipole antenna,
    4a, 4b and 4e
    feed element,
    4c, 4d, 5, 7, 13a, 13b, 14a and 14b
    parasitic element,
    6, 8 and 61 to 67
    parasitic element array,
    13 and 14
    parasitic element pair,
    10, 11 and 12
    grounding conductor,
    20
    feeder line,
    100, 100A, 100B, 100C, 100D and 100E
    antenna apparatus,
    200
    wireless communication apparatus, and
    S6, S8 and S60
    pseudo-slot opening.



    Claims

    1. An antenna apparatus (100,100A,100B,100C,100D,100E) comprising:

    a dielectric substrate (1) having first and second surfaces;

    a dipole antenna (4,4A,4B,4C) including a first feed element (4a) formed on the first surface of the dielectric substrate (1) and connected to a feeder line (20), and a second feed element (4b,4e) formed on the second surface of the dielectric substrate (1) and connected to a ground conductor (20), the dipole antenna (4,4A,4B,4C) having an electrical length (L4) of substantially 1/2 of a wavelength of a high-frequency signal to be radiated; and

    at least three first parasitic element arrays (6,61-67), each of the first parasitic element arrays (6,61-67) including a plurality of first parasitic elements (5) formed on the first surface of the dielectric substrate (1),
    in each of the first parasitic element arrays (6,61-67), each of the plurality of first parasitic elements (5) has a strip shape parallel to a longitudinal direction of the dipole antenna (4,4A,4B,4C), each strip shape having sides and ends, and the plurality of first parasitic elements (5) being arranged at predetermined first intervals (L5), each of the first intervals (L5) being provided between opposing sides of each pair of first parasitic elements (5) adjacent to each other in a direction perpendicular to the longitudinal direction of the dipole antenna (4,4A,4B,4C), so as to be electromagnetically coupled to each other, and

    the at least three first parasitic element arrays (6,61-67) are arranged parallel to one another at predetermined second intervals (L6), each pair of first parasitic elements (5) being adjacent to each other in a direction parallel to the longitudinal direction of the dipole antenna (4,4A,4B,4C), so that each of first pseudo-slot openings (S6, S60) is formed between each pair of adjacent first parasitic element arrays (6,61-67), the first pseudo-slot openings (S6, S60) allowing a radio wave from the dipole antenna (4,4A,4B,4C) to propagate therethrough as magnetic currents, and

    wherein the first interval (L5) is set to substantially equal to or smaller than 1/8 of the wavelength,

    wherein

    a) the antenna apparatus further (100B, 100C, 100E) comprises at least three second parasitic element arrays (8), each of the second parasitic element arrays (8) including a plurality of second parasitic elements (7) formed on the second surface of the dielectric substrate (1),
    wherein, in each of the second parasitic element arrays (8), each of the plurality of second parasitic elements (7) has a strip shape parallel to the longitudinal direction of the dipole antenna (4,4A,4B,4C), and the plurality of second parasitic elements (7) being arranged at predetermined third intervals (L7) so as to be electromagnetically coupled to each other,
    wherein the at least three second parasitic element arrays (8) are arranged parallel to one another at predetermined fourth intervals (L8) so that each of second pseudo-slot openings (S8) is formed between each pair of adjacent second parasitic element arrays (8), the second pseudo-slot openings (S8) allowing the radio wave from the dipole antenna (4,4A,4B,4C) to propagate therethrough as magnetic currents, and
    wherein the dipole antenna (4,4A,4B,4C) further includes:

    a third parasitic element (4d) formed on the second surface so as to be opposed to the first feed element (4a); and

    a fourth parasitic element (4c) formed on the first surface so as to be opposed to the second feed element (4b,4e); and/or

    b) an electrical length of the first feed element (4a) and an electrical length of the second feed element (4e) are set to be different from each other, and/or

    c) the antenna apparatus (100, 100E) further comprises at least one parasitic element pair (13,14), each of the at least one parasitic element pair (13,14) includes two parasitic elements (13a,13b,14a,14b) formed on at least one of the first and second surfaces and operates as a reflector, wherein each of the two parasitic elements (13a,13b,14a,14b) has a strip shape and the two parasitic elements (13a,13b,14a,14b) are formed in a straight line so as to be opposed to and be electromagnetically coupled to the dipole antenna (4,4A,4B,4C), the straight line being parallel to the longitudinal direction of the dipole antenna (4,4A,4B,4C) and being located on an opposite side of the dipole antenna (4,4A,4B,4C) from the at least three first parasitic element arrays (6,61-67).


     
    2. The antenna apparatus (100,100A,100B,100C,100D,100E) as claimed in claim 1, wherein the second interval (L6) is set to substantially equal to or smaller than 1/10 of the wavelength.
     
    3. The antenna apparatus (100,100B,100C,100E) as claimed in claim 1 or 2,
    wherein each first parasitic element (5) in one of the pair of adjacent first parasitic element arrays (6) is opposed to a corresponding first parasitic element (5) in another first parasitic element array (6) at their respective adjacent ends.
     
    4. The antenna apparatus (100A,100E) as claimed in claim 1 or 2,
    wherein each first parasitic element (5) in one of the pair of adjacent first parasitic element arrays (61-67) is arranged so as to be shifted by a predetermined distance in a direction perpendicular to the longitudinal direction of the dipole antenna (4,4A,4B,4C) from a corresponding first parasitic element (5) in another first parasitic element array (61-67).
     
    5. The antenna apparatus (100B, 100C, 100E) as claimed in alternative a) of claim 1, wherein the third interval (L7) is set to substantially equal to or smaller than 1/8 of the wavelength.
     
    6. The antenna apparatus (100D,100E) as claimed in any one of claims 1 to 6, except for alternative b) of claim 1 and claims depending thereon, wherein an electrical length of the first feed element (4a) and an electrical length of the second feed element (4e) are set to be substantially equal to each other.
     
    7. A wireless communication apparatus (200) comprising the antenna apparatus (100,100A,100B,100C,100D,100E) as claimed in any one of claims 1 to 6.
     


    Ansprüche

    1. Antennenvorrichtung (100, 100A, 100B, 100C, 100D, 100E), mit:

    einem dielektrischen Substrat (1) mit einer ersten und einer zweiten Oberfläche,

    einer Dipolantenne (4, 4A, 4B, 4C) mit einem ersten Speiseelement (4a), das auf der ersten Oberfläche des dielektrischen Substrats (1) gebildet und mit einer Speisungsleitung (20) verbunden ist, und einem zweiten Speiseelement (4b, 4e), das auf der zweiten Oberfläche des dielektrischen Substrats (1) gebildet und mit einem Masseleiter (20) verbunden ist, wobei die Dipolantenne (4, 4A, 4B, 4C) eine elektrische Länge (L4) von im Wesentlichen 1/2 einer Wellenlänge eines abzustrahlenden Hochfrequenzsignals aufweist, und

    wenigstens drei ersten Parasitelementanordnungen (6, 61-67), wobei jede der ersten Parasitelementanordnungen (6, 61-67) mehrere erste Parasitelemente (5) aufweist, die auf der ersten Oberfläche des dielektrischen Substrats (1) gebildet sind,
    in jeder der ersten Parasitelementanordnungen (6, 61-67) jede der mehreren ersten Parasitelemente (5) eine Streifenform parallel zu einer Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) aufweist, wobei jede Streifenform Seiten und Enden aufweist und die mehreren ersten Parasitelemente (5) mit vorbestimmten ersten Intervallen (L5) angeordnet sind, wobei jedes der ersten Intervalle (L5) zwischen gegenüberliegenden Seiten eines jeden Paares von ersten Parasitelementen (5) vorgesehen ist, die in einer Richtung senkrecht zu der Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) benachbart sind, um elektromagnetisch miteinander gekoppelt zu sein, und

    die wenigstens drei ersten Parasitelementanordnungen (6, 61-67) parallel zueinander mit vorbestimmten zweiten Intervallen (L6) angeordnet sind, wobei jedes Paar der ersten Parasitelemente (5) zueinander in einer Richtung parallel zu der Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) benachbart ist, so dass jede von ersten Pseudo-Schlitzöffnungen (S6, S60) zwischen jedem Paar von benachbarten ersten Parasitelementanordnungen (6, 61-67) gebildet ist, wobei die ersten Pseudo-Schlitzöffnungen (S6, S60) einer Radiowelle von der Dipolantenne (4, 4A, 4B, 4C) erlauben, sich als magnetische Ströme darin auszubreiten, und

    wobei das erste Intervall (L5) im Wesentlichen gleich oder kleiner als 1/8 der Wellenlänge eingestellt ist,

    wobei

    a) die Antennenvorrichtung (100B, 100C, 100E) ferner wenigstens drei zweite Parasitelementanordnungen (8) aufweist, wobei jede der zweiten Parasitelementanordnungen (8) mehrere zweite Parasitelemente (7) aufweist, die auf der zweiten Oberfläche des dielektrischen Substrats (1) gebildet sind,
    wobei in jeder der zweiten Parasitelementanordnungen (8) jedes der mehreren zweiten Parasitelemente (7) eine Streifenform parallel zu der Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) besitzt und die mehreren zweiten Parasitelemente (7) mit vorbestimmten dritten Intervallen (L7) angeordnet sind, um elektromagnetisch miteinander gekoppelt zu sein,
    wobei die wenigstens drei zweiten Parasitelementanordnungen (8) parallel zueinander mit vorbestimmten vierten Intervallen (L8) angeordnet sind, so dass jede von zweiten Pseudo-Schlitzöffnungen (S8) zwischen jedem Paar von benachbarten zweiten Parasitelementanordnungen (8) gebildet ist, wobei die zweiten Pseudo-Schlitzöffnungen (S8) der Radiowelle von der Dipolantenne (4, 4A, 4B, 4C) erlauben, sich als magnetische Ströme darin auszubreiten, und
    wobei die Dipolantenne (4, 4A, 4B, 4C) ferner umfasst:

    ein drittes Parasitelement (4D), das auf der zweiten Oberfläche gebildet ist, um dem ersten Speiseelement (4a) gegenüberzuliegen, und

    ein viertes Parasitelement (4c), das auf der ersten Oberfläche gebildet ist, um dem zweiten Speiseelement (4b, 4e) gegenüberzuliegen, und/oder

    b) eine elektrische Länge des ersten Speiseelements (4a) und eine elektrische Länge des zweiten Speiseelements (4e) unterschiedlich voneinander eingestellt sind, und/oder

    c) die Antennenvorrichtung (100, 100E) ferner wenigstens ein Parasitelementpaar (13, 14) aufweist, wobei jedes des wenigstens einen Parasitelementpaares (13, 14) zwei Parasitelemente (13a, 13b, 14a, 14b) aufweist, die auf der ersten und/oder der zweiten Oberfläche gebildet sind, und als ein Reflektor arbeitet,
    wobei jedes der zwei Parasitelemente (13a, 13b, 14a, 14b) eine Streifenform aufweist und die zwei Parasitelemente (13a, 13b, 14a, 14b) in einer geraden Linie gebildet sind, so dass sie der Dipolantenne (4, 4A, 4B, 4C) gegenüberliegen und elektromagnetisch mit dieser gekoppelt sind, wobei die gerade Linie parallel zu der Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) ist und an einer Seite der Dipolantenne (4, 4A, 4B, 4C) gegenüberliegend zu den wenigstens drei ersten Parasitelementanordungen (6, 61-67) angeordnet ist.


     
    2. Antennenvorrichtung (100, 100A, 100B, 100C, 100D, 100E) nach Anspruch 1,
    wobei das zweite Intervall (L6) im Wesentlichen gleich oder kleiner als 1/10 der Wellenlänge eingestellt ist.
     
    3. Antennenvorrichtung (100, 100B, 100C, 100E) nach Anspruch 1 oder 2,
    wobei jedes erste Parasitelement (5) in einem des Paares von benachbarten ersten Parasitelementanordnungen (6) einem entsprechenden ersten Parasitelement (5) in einer anderen ersten Parasitelementanordnung (6) an deren jeweils benachbarten Enden gegenüberliegt.
     
    4. Antennenvorrichtung (100A, 100E) nach Anspruch 1 oder 2,
    wobei jedes erste Parasitelement (5) in einem des Paares von benachbarten ersten Parasitelementanordnungen (61-67) so angeordnet ist, dass es um eine vorbestimmte Entfernung in einer Richtung senkrecht zu der Längsrichtung der Dipolantenne (4, 4A, 4B, 4C) gegenüber einem entsprechenden ersten Parasitelement (5) in einer anderen ersten Parasitelementanordnung (61-67) versetzt ist.
     
    5. Antennenvorrichtung (100B, 100C, 100E) nach Alternative a) von Anspruch 1,
    wobei das dritte Intervall (L7) im Wesentlichen gleich oder kleiner als 1/8 der Wellenlänge eingestellt ist.
     
    6. Antennenvorrichtung (100D, 100E) nach einem der Ansprüche 1 bis 6, mit Ausnahme von Alternative b) von Anspruch 1 und davon abhängigen Ansprüchen,
    wobei eine elektrische Länge des ersten Speiseelements (4a) und eine elektrische Länge des zweiten Speiseelements (4e) im Wesentlichen gleich zueinander eingestellt sind.
     
    7. Drahtloskommunikationsvorrichtung (200) mit der Antennenvorrichtung (100, 100A, 100B, 100C, 100D, 100E) nach einem der Ansprüche 1 bis 6.
     


    Revendications

    1. Dispositif d'antenne (100, 100A, 100B, 100C, 100D, 100E) comprenant:

    un substrat diélectrique (1) ayant des première et deuxième surfaces,

    une antenne dipôle (4, 4A, 4B, 4C) comprenant un premier élément d'alimentation (4a) formé sur la première surface du substrat diélectrique (1) et connecté à une ligne d'alimentation (20), et un deuxième élément d'alimentation (4b, 4e) formé sur la deuxième surface du substrat diélectrique (1) et connectée à un conducteur de masse (20), l'antenne dipôle (4, 4A, 4B, 4C) ayant une longueur électrique (L4) pour l'essentiel égale à 1/2 d'une longueur d'onde d'un signal haute fréquence à émettre, et

    au moins trois premiers ensembles d'éléments parasites (6, 61-67), chacun des premiers ensembles d'éléments parasites (6, 61-67) comprenant une pluralité de premiers éléments parasites (5) formés sur la première surface du substrat diélectrique (1),
    dans chacun des premiers ensembles d'éléments parasites (6, 61-67), chacun de la pluralité des premiers éléments parasites (5) présente une forme de bande parallèle à une direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C), chaque forme de bande ayant des côtés et des extrémités, et la pluralité de premiers éléments parasites (5) étant disposée à des premiers intervalles (L5) prédéterminés, chacun des premiers intervalles (L5) étant prévu entre des côtés opposés de chaque paire de premiers éléments parasites (5) adjacents les uns aux autres dans une direction perpendiculaire à la direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C) de manière à être couplés de façon électromagnétique les uns aux autres, et

    lesdits au moins trois premiers ensembles d'éléments parasites (6, 61-67) sont disposés parallèlement les uns aux autres à des deuxièmes intervalles (L6) prédéterminés, chaque paire de premiers éléments parasites (5) étant adjacente l'une à l'autre dans une direction parallèle à la direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C) de sorte que chacune de premières ouvertures de pseudo-fente (S6, S60) est formée entre chaque paire de premiers ensembles d'éléments parasites (6, 61-67) adjacents, les premières ouvertures de pseudo-fente (S6, S60) permettant à une onde radio de l'antenne dipôle (4, 4A, 4B, 4C) de se propager à travers celle-ci en tant que de courants magnétiques, et

    dans lequel le premier intervalle (L5) est réglé pour être pour l'essentiel égal ou inférieur à 1/8 de la longueur d'onde,

    dans lequel

    a) le dispositif d'antenne (100B, 100C, 100E) comprend en outre au moins trois deuxièmes ensembles d'éléments parasites (8), chacun des deuxièmes ensembles d'éléments parasites (8) comprenant une pluralité de deuxièmes éléments parasites (7) formés sur la deuxième surface du substrat diélectrique (1),
    dans lequel, dans chacun des deuxièmes ensembles d'éléments parasites (8), chacun de la pluralité de deuxièmes éléments parasites (7) présente une forme de bande parallèle à la direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C), et la pluralité de deuxièmes éléments parasites (7) étant disposée à des troisièmes intervalles (L7) prédéterminés de manière à être couplés de façon électromagnétique les uns aux autres,
    dans lequel lesdits au moins trois deuxièmes ensembles d'éléments parasites (8) sont disposés parallèlement les uns aux autres à des quatrièmes intervalles (L8) prédéterminés de sorte que chacune de deuxièmes ouvertures de pseudo-fente (S8) est formée entre chaque paire de deuxièmes ensembles d'éléments parasites (8) adjacents, les deuxièmes ouvertures de pseudo-fente (S8) permettant à l'onde radio de l'antenne dipôle (4, 4A, 4B, 4C) de se propager à travers elles en tant que courants magnétiques, et
    dans lequel l'antenne dipôle (4, 4A, 4B, 4C) comprend en outre:

    un troisième élément parasite (4d) formé sur la deuxième surface de manière à être opposé au premier élément d'alimentation (4a), et

    un quatrième élément parasite (4c) formé sur la première surface de manière à être opposé au deuxième élément d'alimentation (4b, 4e), et/ou

    b) une longueur électrique du premier élément d'alimentation (4a) et une longueur électrique du deuxième élément d'alimentation (4e) sont définies pour être différentes l'une de l'autre, et/ou

    c) le dispositif d'antenne (100, 100E) comprend en outre au moins une paire d'éléments parasites (13, 14), chacune de ladite au moins une paire d'éléments parasites (13, 14) comprend deux éléments parasites (13a, 13b, 14a, 14b) formés sur la première et/ou la deuxième surfaces et fonctionne en tant que réflecteur,
    dans lequel chacun des deux éléments parasites (13a, 13b, 14a, 14b) présente une forme de bande et les deux éléments parasites (13a, 13b, 14a, 14b) sont formés en une ligne droite de manière à être opposés et couplés de façon électromagnétique à l'antenne dipôle (4, 4A, 4B, 4C), la ligne droite étant parallèle à la direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C) et étant située sur un côté de l'antenne dipôle (4, 4A, 4B, 4C) opposé auxdits au moins trois premiers ensembles d'éléments parasites (6, 61-67).


     
    2. Dispositif d'antenne (100, 100A, 100B, 100C, 100D, 100E) selon la revendication 1,
    dans lequel le deuxième intervalle (L6) est réglé pour être pour l'essentiel égal ou inférieur à 1/10 de la longueur d'onde.
     
    3. Dispositif d'antenne (100, 100B, 100C, 100E) selon la revendication 1 ou 2,
    dans lequel chaque premier élément parasite (5) dans l'un de la paire de premiers ensembles d'éléments parasites (6) adjacents est opposé à un premier élément parasite (5) correspondant dans un autre premier ensemble d'éléments parasites (6) à leurs extrémités adjacentes respectives.
     
    4. Dispositif d'antenne (100A, 100E) selon la revendication 1 ou 2,
    dans lequel chaque premier élément parasite (5) dans l'un de la paire de premiers ensembles d'éléments parasites (61-67) adjacents est agencé de manière à être décalé d'une distance prédéterminée dans une direction perpendiculaire à la direction longitudinale de l'antenne dipôle (4, 4A, 4B, 4C) à partir d'un premier élément parasite (5) correspondant dans un autre premier ensemble d'éléments parasites (61-67).
     
    5. Dispositif d'antenne (100B, 100C, 100E) selon la variante a) de la revendication 1,
    dans lequel le troisième intervalle (L7) est réglé pour être pour l'essentiel égal ou inférieur à 1/8 de la longueur d'onde.
     
    6. Dispositif d'antenne (100D, 100E) selon l'une quelconque des revendications 1 à 6, à l'exception de la variante b) de la revendication 1 et des revendications qui en dépendent,
    dans lequel une longueur électrique du premier élément d'alimentation (4a) et une longueur électrique du deuxième élément d'alimentation (4e) sont définies pour être pour l'essentiel égales l'une à l'autre.
     
    7. Dispositif de communication sans fil (200) comprenant le dispositif d'antenne (100, 100A, 100B, 100C, 100D, 100E) selon l'une quelconque des revendications 1 à 6.
     




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    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description