JP2016092564A - Circular polarized antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and down-size an antenna structure, while maintaining the fractional bandwidth of various characteristics well, by narrowing the feeder line width without thinning a substrate.SOLUTION: On the surface of a printed board 60 having a ground pattern formed entirely on the back side, a plurality of radiation elements 11-44 are formed while being arranged in matrix at a predetermined mutual interval, feeder lines 15-45 are formed in a space surrounded by the radiation elements 11-44, and power having a preset phase shift, sequentially, is supplied from the feeder lines 15-45 to the plurality of radiation elements 11-44. Furthermore, a ground pattern is formed to surround the plurality of radiation elements 11-44 and feeder lines 15-45, on the surface of the printed board 60, while spaced apart by a non-conductive area of a constant width.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circularly polarized antenna using a patch antenna element.

  Satellite broadcast receiver, wireless LAN (Local Area Network), GPS (Global Positioning System), ETC (Electronic Toll Collection System), DSRC (Dedicated Short Range Communications), VICS (Vehicle Information and Communication System) (registered trademark), etc. In a base station used in this communication system, an antenna using circular polarization is used.

  For example, Patent Document 1 describes a patch antenna using a microstrip line as a directional planar antenna for microwaves. In this antenna, a plurality of patch antenna elements are arranged on a planar dielectric substrate so that four patch antenna elements are positioned at the apex of the quadrilateral, thereby forming a plurality of subarrays. A microstrip feed line including a phase shifter and a distributor is arranged for each sub-array, and power is sequentially fed to the four patch antenna elements by 90 degrees by the microstrip feed line. , To generate circularly polarized waves.

JP-A-2-180408

  However, in the antenna described in Patent Document 1, it is necessary to set the distance between the patch antenna element and the microstrip feed line sufficiently large in order to reduce the coupling between the patch antenna element and the microstrip feedline. As a result, there is a problem that an increase in the size of the antenna is inevitable. In particular, when the antenna is used in a high frequency band, the line width of the feed line becomes larger than the size of the patch antenna element, so the influence between the patch antenna element and the feed line becomes large, and the axial ratio characteristics Deterioration of is inevitable. On the other hand, if the thickness of the printed circuit board is reduced, the width of the feed line for obtaining a desired impedance can be reduced. However, when this is done, the radiation efficiency of the antenna is lowered, and the ratio bandwidth of various characteristics such as a voltage standing wave ratio (VSWR) characteristic is narrowed.

  On the other hand, an antenna device has been proposed in which a plurality of substrates or multilayer substrates are used to prevent the antenna from becoming large, and a feed line is formed on a surface different from a surface on which a radiating element such as a patch antenna element is formed. However, such a configuration causes an increase in the number of parts and a complicated structure, and an increase in cost is inevitable.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to reduce the width of the feeder line without reducing the thickness of the substrate, thereby maintaining the specific bandwidth of various characteristics satisfactorily. An object of the present invention is to provide a circularly polarized antenna that can be simplified in structure and reduced in size.

  In order to achieve the above object, the first aspect of the circularly polarized antenna according to the present invention is the back side of the first surface of the planar dielectric substrate in which the first ground pattern is formed on the first surface. A plurality of radiating elements are formed on the second surface in a state of being arranged in a matrix at predetermined intervals, and a feed line is formed in a space surrounded by the radiating elements on the second surface. , And the power is sequentially fed to the plurality of radiating elements by a predetermined amount by the feeding line. Further, a second ground pattern set at the same potential as the first ground pattern is formed between at least the plurality of radiating elements on the second surface of the planar dielectric substrate and the feeder line. It is what I did.

  In a second aspect of the circularly polarized antenna according to the present invention, the second grounding pattern is formed in a state in which the second grounding pattern is arranged close to each other with a non-conducting region having a predetermined width along both sides of the feed line. It is a thing.

  In a third aspect of the circularly polarized antenna according to the present invention, the second grounding pattern surrounds the radiating element with a non-conducting region having a predetermined width along an outer edge of the plurality of radiating elements. It is to be formed.

  A fourth aspect of the circularly polarized antenna according to the present invention has a phase shifter and a distributor in which the feed lines are arranged independently of each other, and the distributor is constituted by a Wilkinson type. Is.

  According to a fifth aspect of the circularly polarized antenna according to the present invention, a plurality of antenna units including the plurality of radiating elements, a feed line, and a second ground pattern are provided on a second surface of the planar dielectric substrate. Arranged in a matrix with a space between each other, the power supply line of each antenna unit feeds power that is sequentially shifted by a preset amount between the antenna units to the radiating element of each antenna unit. It is what you do.

  According to the first aspect of the present invention, the plurality of radiating elements and the feed line are formed on the same surface of the planar dielectric substrate, and the second space is provided at least in the space between the plurality of radiating elements and the feed line. The ground pattern is formed. For this reason, the second grounding pattern electromagnetically shields between the radiating element and the feed line, and the amount of coupling is kept low, thereby radiating while maintaining various characteristics such as the radiation characteristics of the antenna. It is possible to reduce the size of the antenna by making it possible to make the arrangement interval between the element and the feeder line closer. In addition, since the radiating element and the feed line can be arranged close to each other on the same plane of the planar dielectric substrate, the number of components and the cost can be reduced without using a multilayer substrate or a plurality of substrates.

  According to the second aspect of the present invention, the second grounding pattern is arranged close to each other at a predetermined interval along both sides of the feeding line, so that the feeding line is connected to the grounded coplanar line. can do. As a result, when designing the same impedance, the line width of the feed line can be reduced without changing the material and thickness of the planar dielectric substrate. This narrowing of the feed line enables the feed line to be bent or folded with a small radius, reducing the installation space for the feed line and narrowing the spacing between the radiating elements, thereby further reducing the size of the antenna. Can be achieved.

  According to the third aspect of the present invention, each of the plurality of radiating elements is surrounded by the second ground pattern. For this reason, the coupling between the radiating elements and between the feed lines can be effectively reduced.

  According to the fourth aspect of the present invention, the phase shifter and the distributor can be arranged independently to enable a design to change the phase difference and the distribution ratio to the radiating element, thereby It becomes possible to easily control the directivity such as side lobe suppression and tilt angle. Moreover, since the arrangement | positioning space | interval of a radiation element can be narrowed by narrowing the said feeder line, a more flexible adjustment can be performed.

  According to the fifth aspect of the present invention, it is possible to provide a circularly polarized array antenna having a small size and excellent radiation characteristics and axial ratio characteristics by arranging a plurality of antenna units side by side on the same substrate.

  That is, according to the present invention, the circularly polarized wave can be simplified and miniaturized while reducing the feed line width without reducing the substrate thickness, thereby maintaining the specific bandwidth of various characteristics well. An antenna can be provided.

The figure which shows the structure of the circularly polarized wave antenna which concerns on one Embodiment of this invention. The figure which expanded and showed one antenna unit among the circularly polarized antennas shown in FIG. The figure which shows the excitation direction of each radiation unit which comprises each antenna unit of the circularly polarized antenna shown in FIG. 1, and the said antenna unit. The figure which shows the change method of the amount of phase shifts with respect to each radiation element of the circularly polarized wave antenna shown in FIG. The figure which shows an example of the measurement result of the vertical surface directivity by the circularly polarized antenna shown in FIG. The figure which shows an example of the measurement result of horizontal plane directivity by the circularly polarized antenna shown in FIG. The figure which shows an example of the measurement result of the diagonal 45 degree plane directivity by the circularly polarized wave antenna shown in FIG. The figure which shows an example of the measurement result of the VSWR characteristic by the circularly polarized antenna shown in FIG. The figure which shows an example of the measurement result of the gain characteristic by the circularly polarized antenna shown in FIG. The figure which shows an example of the measurement result of the antenna axial ratio characteristic by the circularly polarized wave antenna shown in FIG. The side view which shows the example of installation of the radio | wireless apparatus using the circularly polarized antenna shown in FIG. The top view which shows the example of installation of the radio | wireless apparatus using the circularly polarized antenna shown in FIG. The figure which looked at the radio | wireless apparatus shown in FIG.11 and FIG.12 in parallel with respect to the baseplate from the earth side to the sky side. The figure which looked at the radio | wireless apparatus shown in FIG.11 and FIG.12 from the front in the baseplate direction.

Embodiments according to the present invention will be described below with reference to the drawings.
[One Embodiment]
(Constitution)
FIG. 1 is a plan view showing a configuration of a right-handed circularly polarized antenna according to an embodiment of the present invention, and 60 shows a printed circuit board as a planar dielectric substrate. The printed circuit board 60 is made of a single layer substrate made of a fluororesin, and a ground pattern is formed on the entire surface excluding the power feeding portion on the back surface which is the first surface.

  On the other hand, on the surface, which is the second surface of the printed circuit board 60, 16 conductive patterns constituting the radiating elements are formed in a 4 × 4 matrix at predetermined intervals. These 16 radiating elements are divided into 2 × 2 pieces to constitute antenna units 10, 20, 30, and 40, respectively. For example, the radiating elements 11 to 14 constitute the antenna unit 10, the radiating elements 21 to 24 constitute the antenna unit 20, the radiating elements 31 to 34 constitute the antenna unit 30, and the radiating elements 41 to 44 constitute the antenna unit 40.

  In addition, on the surface of the printed circuit board 60, the feeding lines 15 and 14 are formed by using empty spaces between the radiating elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44 for the antenna units 10 to 40, respectively. 25, 35, 45 are formed. These feed lines 15 to 45 supply power to each of the radiating elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44 from the feed unit 50 provided at the center of the printed circuit board 60. , Each having a plurality of phase shifters and a plurality of distributors.

  For example, the feed line 15 of the antenna unit 10 includes a first-stage phase shifter 151, a first-stage distributor 152, and a second-stage phase shifter 153, as shown in an enlarged view in FIG. The second stage Wilson distributors 154 and 157 and the third stage phase shifters 155, 156, 158, and 159 are included. Among these, the first-stage phase shifter 151 determines the phase of the power supplied from the power supply unit 50 to the antenna unit 10, and is set to a delay amount (0 °) here. The second-stage phase shifter 153 is curved in an S shape and gives a 180 ° phase difference between the radiating elements 11 and 12 and the radiating elements 13 and 14. The third-stage phase shifters 155, 156 and 158, 159 give a phase difference of 90 ° between the radiating element 11 and the radiating element 12 and between the radiating element 13 and the radiating element 14, respectively.

  The first phase shifters 251, 351, 451 of the other feed lines 25, 35, 45 determine the phase of power supplied from the power supply unit 50 to the antenna units 20, 30, 40, respectively. The amount of phase shift is set to 90 °, 180 °, and 270 °, respectively. The phase shifters and distributors other than the first-stage phase shifters 251, 351, 451 of the other feed lines 25, 35, 45 are the same as the feed line 15, and will be described here. Is omitted.

  By the way, the surface of the printed circuit board 60 is filled with spaces between the radiation elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44 and the feeder lines 15, 25, 35, and 45. In addition, a ground pattern 70 is formed. For example, as shown in FIG. 1, the ground pattern 70 is formed so as to surround each of the radiating elements 11 to 14, 21 to 24, 31 to 34 and 41 to 44 with a non-conductive portion having a predetermined width along the outer edge thereof. The ground pattern 70 is formed in a state where it is formed and close to both sides of the feeder lines 15, 25, 35, 45 with a non-conductive portion having a predetermined width therebetween.

  Also, through holes (not shown) are provided at regular intervals on the outer edge of the ground pattern 70, and the ground pattern 70 is connected to a ground pattern (not shown) formed on the back surface of the printed circuit board 60 through these through holes. They are connected to have the same potential.

  2 and FIG. 3 and FIG. 4 to be described later, for convenience of illustration, the radiating elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44, the feed lines 15, 25, 35, and 45, and the ground pattern 70 are illustrated. The hatched display for is omitted.

(Operation and effect)
Because of the configuration as described above, the power output from the power feeding unit 50 is first input to the first-stage distributor 152 without delay through the first-stage phase shifter 151 in the antenna unit 10. After being bifurcated by the distributor 152, one of them is further bifurcated by a Wilkinson distributor 154 in the second stage. Then, one of the electric powers is supplied to the radiating element 11 through the third-stage phase shifter 155 without delay, and the other electric power is shifted by 90 ° by the shifter 156 and supplied to the radiating element 12. . On the other hand, the other power bifurcated by the first-stage distributor 152 is phase-shifted by 180 ° by the second-stage phase shifter 153 and then bifurcated by the Wilkinson distributor 157. Then, one of the electric powers is supplied to the radiating element 13 through the third-stage phase shifter 158 without delay, and the other electric power is delayed by 90 ° by the phase shifter 159 and supplied to the radiating element 14. . As a result, as shown in FIG. 3, the radiating elements 11 to 14 of the antenna unit 10 are excited by electric power whose phase is sequentially shifted by 90 ° with reference to 0 ° phase-shifted electric power.

  Next, in the antenna unit 20, the phase of the power output from the power feeding unit 50 is first shifted by 90 ° by the first-stage phase shifter 251. Then, the phase is sequentially shifted by 90 ° by the second-stage distributor, the third-stage phase shifter, the Wilkinson-type distributor, and the third-stage phase shifter, and then given to the radiating elements 21 to 24. As a result, the radiating elements 21 to 24 of the antenna unit 20 are sequentially shifted in phase by 90 ° with reference to the power shifted by 90 ° from the power applied to the antenna unit 10 as shown in FIG. Excited by electric power.

  Subsequently, in the antenna unit 30, the phase of the power output from the power feeding unit 50 is first shifted by 180 ° by the first-stage phase shifter 351. The phase is sequentially shifted by 90 ° by the second-stage distributor, the third-stage phase shifter, the Wilkinson-type distributor, and the third-stage phase shifter, and then given to the radiating elements 31 to 34. As a result, the radiating elements 31 to 34 of the antenna unit 30 are sequentially shifted in phase by 90 ° with reference to the power shifted by 180 ° from the power applied to the antenna unit 10 as shown in FIG. Excited by electric power.

  Similarly, in the antenna unit 40, the power output from the power supply unit 50 is first phase-shifted by 270 ° by the first-stage phase shifter 451. Then, the phase is sequentially shifted by 90 ° by the second-stage distributor, the third-stage phase shifter, the Wilkinson-type distributor, and the third-stage phase shifter, and then given to the radiating elements 41 to 44. As a result, the radiating elements 41 to 44 of the antenna unit 40 sequentially shift their phases by 90 ° with reference to the power shifted by 270 ° from the power supplied to the antenna unit 10 as shown in FIG. Excited by electric power.

  Thus, according to the circularly polarized antenna of the present embodiment, right circularly polarized waves are radiated by the four antenna units 10 to 40. FIG. 5, FIG. 6 and FIG. 7 show measurement results of vertical directivity, horizontal directivity and oblique 45 ° directivity in the band of 5.6 to 6.0 GHz by the circularly polarized antenna configured as described above. It is a figure which shows an example. As shown in the figure, the side lobe is small and uniform directivity can be obtained regardless of any of vertical directivity, horizontal directivity, and oblique 45 ° directivity.

  FIGS. 8, 9 and 10 also show examples of measurement results of VSWR characteristics, gain characteristics and axial ratio characteristics in the band of 5.6 to 6.0 GHz. As is apparent from these characteristics, good characteristics can be obtained for the VSWR characteristics, the gain characteristics, and the axial ratio characteristics in the band of 5.6 to 6.0 GHz.

  Moreover, according to the circularly polarized wave antenna of this embodiment, the following effects are produced. That is, as shown in FIG. 1, the radiating elements 11 to 14, 21 to 24, 31 to 34, 41 to 44 of the excitation antenna units 10 to 40 and the phase shifts that configure the feed lines 15, 25, 35, and 45. Both the container and the distributor are surrounded by the ground pattern 70 in a state of being close to each other with a non-conducting region having a predetermined width. In other words, the feed lines 15, 25, 35, 45 are constituted by grounded coplanar lines. For this reason, when designing the antenna under the condition that the impedances are the same, the line widths of the feed lines 15, 25, 35, and 45 can be reduced without changing the material and thickness of the printed circuit board 60. It becomes possible.

  Thus, by narrowing the line width of the feed lines 15, 25, 35, 45, the portions constituting the phase shifter and distributor of the feed lines 15, 25, 35, 45 are curved or folded with a small radius. As a result, the installation space of the feeder lines 15, 25, 35, 45 can be reduced, and the arrangement interval of the radiating elements 11-14, 21-24, 31-34, 41-44 can be reduced, and the antenna It becomes possible to achieve further miniaturization.

  Moreover, since it becomes possible to suppress the influence with respect to the radiation elements 11-14, 21-24, 31-34, 41-44 of the electric field which leaks from feeder line 15,25,35,45, the radiation characteristic of an antenna is made. While maintaining good, it is possible to make the arrangement intervals between the radiating elements 11 to 14, 21 to 24, 31 to 34, 41 to 44 and the feeder lines 15, 25, 35, 45 closer, thereby Also, the antenna can be miniaturized.

  Furthermore, since the thickness of the printed circuit board 60 can be maintained at a certain thickness or more, the ground pattern formed on the back surface of the printed circuit board 60 and the radiating elements 11 to 14, 21 to 24, 31 formed on the front surface of the printed circuit board 60. 34, 41 to 44 can be sufficiently separated from each other, whereby the specific band of the VSWR characteristic can be widened and good radiation efficiency can be obtained.

  Furthermore, since the radiating elements 11 to 14, 21 to 24, 31 to 34, 41 to 44 and the feed lines 15, 25, 35, and 45 can be formed on the same surface of the printed board 60, a multilayer board or a plurality of boards are not required. Thus, the number of parts can be reduced and the cost can be reduced. The printed circuit board radiating element and the feeder line are suitable for mass production because they can be easily manufactured by a normal printed pattern manufacturing method and a component surface mounting method. Therefore, the cost of the antenna can be reduced.

  Moreover, according to this embodiment, in the feed lines 15, 25, 35, and 45, each phase shifter and each distributor are arranged independently. For this reason, the design for changing the phase difference and distribution ratio with respect to the radiation elements 11-14, 21-24, 31-34, 41-44 can be enabled. For example, as shown in FIG. 4, when the amount of phase shift by the second-stage phase shifter 153 is increased, the lengths of both ends of the semicircular curved portion of the phase shifter 153 are extended. . Further, when the phase shift amount of the third-stage phase shifter 159 is increased, the line length of the phase shifter 159 is extended while rotating the radiating element 14 around the center point thereof. Further, when the stack interval between the radiating elements 11 and 12 is changed, the line length between the Wilkinson distributor 154 and the third-stage phase shifters 155 and 156 is expanded and contracted. If comprised as mentioned above, it will become possible to control directivity, such as suppression of a side lobe and a tilt angle.

  Further, by using the Wilkinson type as the distributors 154, 157 closest to the radiating elements 11-14, 21-24, 31-34, 41-44, it is possible to mount a chip resistor. As a result, it is possible to secure a coupling attenuation amount with each of the radiating elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44, and to reduce the axial ratio. If the axial ratio is good, the chip resistor can be omitted.

(Use)
Next, the use of the circularly polarized antenna configured as described above will be described.
FIG. 11 shows an installation example of the wireless device 1 for VICS using the circularly polarized antenna according to the present embodiment.

  The wireless device 1 is attached on a column 2 installed on the shoulder of the road. At this time, the installation position of the wireless device 1 is 4 to 4.5 m away from the center line and 5 to 6 m above the road surface, for example, as shown in FIG. Is set as follows. Further, the mounting angle of a base plate 101 described later is set so as to be inclined by 15 ° on the road surface side with respect to the vertical direction.

  The broadcast target area (reception area) for the road of the wireless device 1 is a predetermined area on the upstream side of each lane as shown by E1 and E2 in FIG. 12, for example, when the road is composed of one lane as described above. Must be set to a range. In order to satisfy this condition, the wireless device 1 is configured as follows. 13 and 14 show the configuration, FIG. 13 is a side view thereof, and FIG. 14 is a front view thereof.

  That is, the wireless device 1 includes a base plate 101, and a support member is attached to the base plate 101. The support member includes a bottom plate 102 and side plates 103 and 104 formed of, for example, sheet metal, and the bottom plate 101 is fixed to the base plate 101 with screws. The side plates 103 and 104 have the angles θ1, θ2 and θ3 in the left and right directions and the up and down directions so that the directions of the surfaces thereof are the directions of the reception areas E1 and E2 of the up and down traveling lanes shown in FIG. θ4 is set for each.

  The circularly polarized antennas 201 and 202 shown in FIG. 1 are attached to the surfaces of the side plates 103 and 104. At this time, as described above, the circularly polarized antennas 201 and 202 include the radiating elements 11 to 14, 21 to 24, 31 to 34, 41 to 44 and the feed lines 15, 25, 35, and 45 as a single unit. Since it has a very simple structure formed on the same surface of the layer printed board 60, it can be easily attached to the side plates 103 and 104. Further, since the size of the printed circuit board 60 is also reduced, the size of the side plates 103 and 104, and hence the size of the wireless device 1 can be reduced. Note that reference numeral 301 shown in FIG. 14 denotes a power feeding unit, which is attached on the bottom plate 102.

  Because of such a configuration, the radio waves radiated from the circularly polarized antennas 201 and 202 have a predetermined directivity, and as shown in FIG. It is transmitted toward reception areas E1 and E2, respectively. Note that the lengths of these receiving areas E1 and E2 in the traveling direction are set to be 70 m or more in consideration of the traveling speed of the vehicle.

  Therefore, a vehicle traveling in each traveling lane on the road and on the road can receive the VICS signal transmitted from the wireless device 1 when passing through the respective reception areas E1 and E2, thereby causing an accident or accident. You can receive information about traffic jams.

[Other Embodiments]
The present invention is not limited to the above embodiment. For example, in the above-described embodiment, 16 radiating elements 11 to 14, 21 to 24, 31 to 34, and 41 to 44 are arranged in a matrix. However, the number of radiating elements may be only four, or sixteen. The number may be greater.

  In addition, the shape of the radiating element and the feeder line, the formation range of the ground pattern formed between the radiating element and the feeder line, the material of the printed circuit board, and the like can be variously modified without departing from the scope of the present invention. is there.

  In short, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Radio | wireless apparatus, 2 ... Support | pillar, 10-40 ... Antenna unit, 11-14, 21-24, 31-34, 41-44 ... Radiation element, 15, 25, 35, 45 ... Feeding line, 50 ... Feeding part , 60 ... printed circuit board, 70 ... ground pattern, 101 ... base plate, 102 ... bottom plate of support member, 103, 104 ... side plate of support member, 151, 153, 155, 156, 159, 251, 351, 451 ... phase shifter , 152 ... distributor, 154, 157 ... Wilkinson distributor, 201, 202 ... circularly polarized antenna.

Claims (5)

A planar dielectric substrate having a first ground pattern formed on a first surface;
A plurality of radiating elements formed in a state of being arranged in a matrix at predetermined intervals on the second surface which is the back side of the first surface of the planar dielectric substrate;
A feeding line that feeds power that is formed in a space surrounded by the plurality of radiating elements on the second surface and that is sequentially shifted by a predetermined amount with respect to the plurality of radiating elements;
A second ground pattern formed between at least the plurality of radiating elements on the second surface and the feeder line and set at the same potential as the first ground pattern. Circularly polarized antenna.   The circularly polarized antenna according to claim 1, wherein the second ground pattern is formed in a state in which the second ground pattern is disposed close to both sides of the feeder line with a non-conductive region having a predetermined width.   The said 2nd grounding pattern is formed so that the said radiation | emission element may be surrounded by the non-conductive area | region of predetermined width along the outer edge of these radiation elements. Circularly polarized antenna.   4. The circular bias according to claim 1, wherein the feeder line includes a phase shifter and a distributor that are independently arranged, and the distributor is configured by a Wilkinson type. Wave antenna.   A plurality of antenna units including the plurality of radiating elements, feed lines, and a second ground pattern are arranged in a matrix in a state of being spaced apart from each other on the second surface of the planar dielectric substrate. 5. The power feeding line of the antenna unit feeds electric power whose phase is sequentially shifted by a predetermined amount between the antenna units to the radiation element of the antenna unit. 6. Circularly polarized antenna.

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