JP2003309428A - Circularly polarized wave antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circularly polarized wave antenna having an antenna characteristic proper to satellite radio broadcasting and satellite communication or the like and capable of realizing downsizing suitable for an on-vehicle antenna through the remarkable reduction in the height. <P>SOLUTION: N antenna elements 15 are stood upright on a feeding board 10 at an equal interval and notches 18 of the antenna elements 15 are energized at a phase difference of 360-degrees/N. For example, A conductive layer 17 of an antenna board comprising the conductor layer 17 placed on one side of a dielectric board 16 is notched to be almost an L-shape to form the notch, the upper end of the notch 18 is exposed to an upper end face of the dielectric board 16 and a microstrip line 19 formed at a position transverse to the notch 18 on the other side of the dielectric board 16 is connected to the conductor layer 17 to configure the antenna element 15, four sets of the antenna elements 15 are stood upright on the feeding board 10 at an equal interval and the notches 18 are energized at a phase difference of 90-degrees. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small circularly polarized antenna suitable for receiving satellite radio broadcasting and communicating with geostationary satellites.

[0002]

2. Description of the Related Art Conventionally, for example, the frequency band is 2.3G.
As a small-sized antenna capable of receiving satellite radio broadcasts using a radio wave of Hz, a 4-wire helical antenna as shown in FIG. 14 is known. The helical antenna shown in the figure has a diameter of about λo / 5 and a height of about λo on the reflector 1.
A cylindrical or cylindrical dielectric body 2 of / 2 (where λo is a free space wavelength of a resonating radio wave) is provided upright. Four radiation conductors 3 are spirally wound around the outer surface of the dielectric 2, and each radiation conductor 3 is fed by an AC power source (not shown) with a phase difference of 90 degrees. There is.

The conventionally known helical antenna constructed as described above is widely adopted because it can favorably receive circularly polarized radio waves used for satellite radio broadcasting in a range from the zenith to a low elevation angle. Has been done.

[0004]

In the above-mentioned 4-wire winding helical antenna, although the height dimension is suppressed to a low level by the wavelength shortening action of the dielectric 2, the frequency of the radio wave to be received is still 2 In the case of 0.3 GHz, the height dimension is about 67 mm, so that the height reduction is insufficient for a vehicle-mounted antenna.

The present invention has been made in view of such circumstances of the prior art, and an object thereof is to have antenna characteristics suitable for satellite radio broadcasting, satellite communication and the like, and to significantly increase the height dimension. An object of the present invention is to provide a circularly polarized antenna that can be shortened and can be miniaturized, which is suitable as an on-vehicle antenna.

[0006]

In order to achieve the above-mentioned object, the circularly polarized wave antenna of the present invention is provided with a notch which is a non-conductor portion extending in a band shape in an antenna substrate, and one end of the notch is provided in the antenna substrate. An antenna element that is exposed to the upper end surface of the antenna and has the other end closed, a feeding board in which N antenna elements (where N is an integer of 3 or more) stand upright at equal intervals, and the notch. And a feeding means for exciting the respective notches of the N antenna elements at 360 ° / N.
The power is supplied with the phase difference of.

In the case of a circularly polarized wave antenna having such a structure, for example, when N = 4, four antenna elements are erected on the feeding board with their directions turned by 90 °, and the notches of each antenna element are turned by 90 °. When the power is supplied with the phase difference of, the linearly polarized waves whose phases are shifted by 90 ° are radiated from the upper ends (open ends) of the excited notches respectively, so circularly polarized radio waves are radiated as a whole. become. Further, when N = 3, three antenna elements are erected on the power feeding board with their directions changed by 120 ° and the notches of the respective antenna elements are changed by 120 °.
Power may be supplied with a phase difference of. In any case, in this configuration, the total length of each notch may be about a quarter of the wavelength of the resonating radio wave on the antenna substrate, so the height dimension is greatly reduced compared to the above-described 4-wire helical antenna. A circularly polarized antenna is obtained.

In the above structure, the notch of each antenna element extends vertically and its upper end is exposed to the upper end surface of the antenna substrate, and a vertical portion extends laterally from the lower end of the vertical portion to close the end. Approximately L having a horizontal portion which is an end
Since it is possible to shorten the length of the vertical portion of the notch, it is possible to further reduce the height dimension of each antenna element, which can promote the reduction in height of the circularly polarized wave antenna, which is preferable when formed in a V shape.

Further, in the above structure, when the antenna substrate has a shape in which the upper end face is shorter than the lower end face and the inclined end face is continuous with the upper end face, when the notch is excited, the upper end face of the antenna substrate and the Since a strong electric field is generated on the inclined end face, the maximum radiation direction shifts from the zenith direction to the low elevation angle side. Therefore, it is effective when receiving radio waves from geostationary satellites on the equator in high latitude areas.

Further, in the above-mentioned structure, one half of one large board in the longitudinal direction and the other half of the other side are respectively used as the antenna boards of the two antenna elements, and 2
When four large antennas are combined so as to be orthogonal to each other in the central portion so that four antenna elements are erected at equal intervals on the power supply substrate, four individual antenna elements are combined. Since the number of parts and the number of assembling steps can be reduced as compared with, it is preferable because the manufacturing cost can be reduced.

For example, as one specific solution, the antenna substrate is provided with a conductor layer on one surface of a dielectric substrate, and the notch is formed by cutting the conductor layer into a strip shape. A microstrip line formed at a position across the notch on the other surface of the dielectric substrate opposite to the one surface, and a microstrip line formed on the dielectric substrate for connecting one end of the microstrip line to the conductor layer. A circular polarization antenna having a through hole and having a configuration in which the conductor layer and the microstrip line are connected to a ground conductor and a feeding terminal, respectively, is preferable. In this case, if an electrode layer facing the conductor layer near the upper end is provided at a position including a region facing the upper end of the notch on the other surface of the dielectric substrate, the conductor layer and the electrode layer Since a capacitance is generated between and, the capacitance is equivalently increased at the upper end of the notch where the highest electric field strength is obtained.
As a result, the resonance frequency is lowered, so that the total length of the notch necessary for resonating the radio wave of the desired frequency can be shortened, and the height reduction of the circularly polarized wave antenna can be further promoted.

As another specific means for solving the problems, the antenna substrate is made of a metal plate, and the notch is formed by cutting the metal plate into a band shape, and the metal plate is formed in the vicinity of the notch. A circular polarization antenna having a connected power supply line and having a configuration in which the metal plate and the power supply line are respectively connected to a ground conductor and a power supply terminal is suitable. When the metal plate is used as the antenna substrate as described above, the notched antenna substrate can be manufactured easily and inexpensively by pressing or the like.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a circularly polarized antenna according to a first embodiment of the present invention, and FIG. 2 is a first embodiment. Explanatory drawing which shows the front and back of one antenna element in a form example,
FIG. 3 is an explanatory view showing the front and back of the power supply board in the first embodiment.

In the circularly polarized antenna shown in FIG. 1, four rectangular plate-shaped antenna elements 15 are turned by 90 ° on a power supply board 10 having a ground conductor 11 formed on almost the entire upper surface thereof. It is constructed by standing upright. As shown in FIG. 3A, power supply terminals (lands) 12 that are not in contact with the ground conductor 11 are formed at four positions on the upper surface of the power supply board 10 at equal intervals. It is connected to the hall 13. In addition, as shown in FIG. 3B, a microstrip line 14 having a predetermined shape connected to the through hole 13 is formed on the lower surface of the power feeding substrate 10.
The microstrip line 14 has a wide portion 14a having a characteristic impedance of 50Ω and a characteristic impedance of 1
The narrow portion 14b of 00Ω is formed to have a predetermined length and is continuous, and the through holes 13 at four locations are formed.
Further, it is possible to supply a high frequency signal whose phase is deviated by 90 °.

As shown in FIG. 2, in the antenna element 15, a conductor layer 17 such as a copper foil is formed on one surface of a rectangular dielectric substrate 16 to form an antenna substrate, and the conductor layer 17 is formed into a strip shape by etching or the like. A notch 18 which is a non-conductor portion is formed by notching. The notch 18 has a vertical portion that extends vertically and has its upper end exposed to the upper end surface of the dielectric substrate 16, and a horizontal portion that extends laterally from the lower end of this vertical portion and that has a closed end. It has a substantially L shape. The lower end of the conductor layer 17 is soldered to the ground conductor 11 of the power supply board 10. Also, the dielectric substrate 1
On the other surface of 6 (the surface on the side where the conductor layer 17 is not formed), a short microstrip line 19 is formed at a position crossing the notch 18, and the upper end of this microstrip line 19 is a through hole. Notch 1 through 20
8 is connected to the conductor layer 17 in the vicinity thereof. Since the lower end portion of the microstrip line 19 is soldered to the power supply terminal 12 of the power supply board 10, it is connected to the microstrip line 14 through the through hole 13.
Further, the formation position of the through hole 20 serving as the feeding point is selected so that the input resistance of the notch 18 and the impedance of the microstrip line 19 at the feeding point match.

The circularly polarized antenna thus constructed is
Since the microstrip line 19 of each antenna element 15 is formed so as to cross the notch 18, the notch 1
An electric field is generated in the width direction of 8 to excite the notch 18.
Since the electric field of the notch 18 becomes maximum at the upper end which is the open end, radio waves are radiated upward from the upper end surface of the dielectric substrate 16. Now, assuming that the wavelength of the electric wave used by this circularly polarized antenna (resonating electric wave) on the power feeding substrate 10 is λef, the microstrip line 14 provided on the power feeding substrate 10
Are formed in the following manner to realize the phase difference feeding in 90 ° increments. At −90 °, the wide portion 14a is set to λe with respect to 0 °.
It is realized by forming it by a length of f / 4. -1
80 ° is realized by forming the narrow portion 14b to be longer than 0 ° by λef / 2. Also, -270
Is realized by forming the narrow portion 14b longer than 0 ° by 180 ° and a phase delay of 180 °, and forming the wide portion 14a longer by −180 ° by λef / 4. This is achieved by adding a 90 ° phase delay.
As a result, each notch 1 of the four antenna elements 15 is passed through the through hole 13 and the microstrip line 19.
Since 8 can be fed with a phase difference of 90 °, linear polarized waves whose phases are shifted by 90 ° are radiated from the upper ends of the excited notches 18, respectively, and circularly polarized radio waves are radiated as a whole. It will be.

In the circularly polarized antenna described above, the total length of each notch 18 whose upper end is an open end may be about a quarter of the wavelength λea on the dielectric substrate 16 of the radio wave to be resonated, and the dielectric Since the wavelength shortening action of the body substrate 16 is also added, the height dimension can be significantly reduced as compared with the conventional 4-wire helical antenna. That is, in the case of the four-wire winding antenna, the height dimension of about one half of the free space wavelength λo of the radio wave is necessary, whereas the circular polarization antenna according to the present embodiment has the height dimension. 1/5 of λo
Since it can be suppressed to the following, it is possible to achieve a low profile suitable for a vehicle-mounted antenna. For example, when the frequency of the radio wave used is 2.3 GHz, the height dimension of the antenna element 15 can be suppressed to about 18 mm in this embodiment. Further, in the circularly polarized antenna according to the present embodiment example, even if the ratio of the lengths of the vertical portion and the horizontal portion of the notch 18 is changed, it is possible to resonate with the radio wave of the same frequency,
By properly selecting the L-shape of the notch 18, there is an advantage that a circularly polarized antenna of a desired size can be easily designed. Furthermore, there is an advantage that impedance matching can be easily achieved by appropriately adjusting the size of the microstrip line 19. Even if the notch 18 has an I-shape with no horizontal portion, its total length can be set to about λea / 4, so that the height dimension can be reduced as compared with the conventional 4-wire helical antenna.

FIG. 4 is an explanatory view showing the front and back of the antenna element according to the second embodiment of the present invention, FIG. 5 is an explanatory view showing the maximum radiation direction of the electric field on the antenna element in the second embodiment, and FIG. [Fig. 6] is a characteristic diagram showing a radiation pattern in the second embodiment, and the portions corresponding to those in Fig. 2 are denoted by the same reference numerals.

In this embodiment, the shape of the dielectric substrate 16 of each antenna element 15 is different from that of the first embodiment. That is, as shown in FIG. 4, in the antenna element 15 used in the second embodiment, the dielectric substrate 16 is formed in a pentagonal shape having the outward inclined end face 16a,
The upper end surface of the dielectric substrate 16 continuous with the inclined end surface 16a is shorter than the lower end surface. In the example of this embodiment,
The sum of the length A of the upper end surface of the dielectric substrate 16, the length B of the inclined end surface 16a and the length C of the short side end surface is set to about 1/4 of the free space wavelength λo of the radio wave, and the inclination is set. The inclination angle of the end face 16a is set to about 45 °.

As shown in FIG. 5A, the antenna element 1
When the dielectric substrate 16 of No. 5 has a rectangular shape with no inclined end face, a strong electric field is generated on the upper end face of the dielectric substrate 16 from which the upper end of the notch 18 appears, so that the maximum radiation direction is near the zenith, and this antenna The element 15 is replaced by the same element 9 as in the first embodiment.
Circularly polarized antennas, each of which is vertically arranged by changing its direction by 0 °, have a high-gain radiation pattern near the zenith, as shown by the broken line in FIG. On the other hand, in the case of the antenna element 15 in which the side not having the notch 18 of the dielectric substrate 16 is cut off as in the present embodiment, as shown in FIG. Since a strong electric field is generated on the upper and inclined end faces 16a, the maximum radiation direction shifts from the zenith direction to the low elevation angle side. As a result, a circularly polarized antenna having four antenna elements 15 shown in FIG. 5 (b), which are arranged upright by changing their directions by 90 ° as in the first embodiment, is shown by a solid line in FIG. , A radiation pattern with a high gain is obtained within a wide elevation angle range from near the zenith to a low elevation angle, and good antenna characteristics can be expected even when receiving radio waves from a geostationary satellite on the equator, for example, in a high latitude area. In FIG. 6, 0 ° indicates a zenith and ± 90 ° indicates a horizontal plane.

FIG. 7 is an explanatory view showing the front and back of the antenna element according to the third embodiment of the present invention, and the portions corresponding to those in FIGS. 2 and 4 are designated by the same reference numerals.

In this embodiment, the notch 18 is formed on the other surface of the dielectric substrate 16 (the surface on which the conductor layer 17 is not formed).
An electrode layer 21 such as a copper foil facing the conductor layer 17 near the upper end is provided at a position including a region facing the upper end. Therefore, in the antenna element 15 shown in FIG. 7, the capacitance generated between the conductor layer 17 and the electrode layer 21 causes
The capacitance is increased at the upper end of the notch 18 where the highest electric field strength is obtained, and the resonance frequency is lower than that in the case where the electrode layer 21 is not provided. Therefore, the antenna element 15 can shorten the total length of the notch 18 required to resonate with a radio wave of a desired frequency, and can further reduce the height of the circular polarization antenna. In addition,
Even in the case where the dielectric substrate 16 of the antenna element 15 has the inclined end face 16a as in the second embodiment, the same effect can be obtained by attaching the electrode layer 21. The electrode layer 21 is the microstrip line 1
Since the same material as that of No. 9 can be formed on the same surface, the manufacturing process does not become complicated even if the electrode layer 21 is attached.

FIG. 8 is a perspective view of a circularly polarized antenna according to the fourth embodiment of the present invention, and FIG. 9 is a perspective view of the second embodiment of the present invention.
It is explanatory drawing which shows the one large board | substrate, and attaches | subjects the same code | symbol to the part corresponding to FIG.

In this embodiment, two antenna elements 1
5 is different from the first embodiment described above in that the large dielectric substrates 22 and 23 in which the fifth dielectric substrate is used in common are used. That is, as shown in FIG. 9A, a conductor layer 17 and a notch 18 are formed on one surface of the large dielectric substrate 22 on one end side (the right end side in the drawing) in the longitudinal direction. Since the microstrip line is formed, the large dielectric substrate 22 can be regarded as the dielectric substrate of the antenna element 15 whose right half in the figure is one. In addition, the large dielectric substrate 22
Since a microstrip line 19 is formed on one surface and a conductor layer and a notch are formed on the other surface (not shown) in approximately half of the other end (the left end in the figure) in the longitudinal direction of the dielectric large substrate 22, About the left half of the figure is another antenna element 15
It can be regarded as a dielectric substrate, and eventually, two antenna elements 15 using the large dielectric substrate 22 as a common base material are integrally formed. Similarly, as shown in FIG.
Approximately one half of the large dielectric substrate 23 on one end side in the longitudinal direction and approximately half of the other large dielectric substrate can be regarded as the respective dielectric substrates of the two antenna elements 15, so that the large dielectric substrate 23 is used as a common base material. The individual antenna elements 15 are formed as an integrated product.

A notch 22a having an open lower end is formed at the center of one dielectric large substrate 22 in the longitudinal direction, and a notch 23a having an open upper end is formed at the center of the other large dielectric substrate 23 in the longitudinal direction. Has been formed. Then, these two large dielectric substrates 22 and 23 are cut into each other by cutting 22
As shown in FIG. 8, the power supply board 1 is formed by combining the a and 23a so that they are vertically overlapped with each other in the central portion.
A circularly polarized wave antenna in which four antenna elements 15 are erected on the 0 at equal intervals is obtained.

As in this embodiment, the large dielectric substrate 22,
When the circularly polarized wave antenna is configured using 23, the number of parts and the number of assembling steps can be significantly reduced as compared with the first embodiment in which the circularly polarized wave antenna is configured by combining four single antenna elements 15. The manufacturing cost can be reduced.

FIG. 10 is a perspective view of a circularly polarized wave antenna according to a fifth embodiment of the present invention, and FIG. 11 is an explanatory view showing the front and back of a power feeding board in the fifth embodiment, and FIGS. Corresponding parts are designated by the same reference numerals.

In this embodiment, three circular antenna elements 15 are combined to form a circularly polarized wave antenna. Each antenna element 15 is the same as that in the first embodiment described above, but a power supply board is used. The ten microstrip lines 14 and the like are different from those of the first embodiment. That is,
In the present embodiment, the three antenna elements 15 are erected on the power feeding board 10 with their orientations changed by 120 °, and the notches 18 of each antenna element 15 are fed with a phase difference of 120 °. Microstrip line 1 on the bottom side of
4 is formed in a shape as shown in FIG. In the figure, the microstrip line 14 is formed by connecting a wide portion 14a having a characteristic impedance of 50Ω and a narrow portion 14c having a characteristic impedance of 86.6Ω, each of which has a predetermined length and is continuous. High-frequency signals having a phase difference of 120 ° from each other can be fed to the three through holes 13. Specifically, by setting the wavelength of the used radio wave on the power supply substrate 10 to be λef, the wide portion 14a is formed to be longer by λef / 3 each, and
A phase delay of ° is realized. In addition, FIG.
As shown in FIG.
The non-contact power supply terminals 12 are formed at three positions at equal intervals, and each power supply terminal 12 is connected to the through hole 13.

FIG. 12 is a perspective view of a circularly polarized antenna according to the sixth embodiment of the present invention, and FIG. 13 is an explanatory view showing two large substrates in the sixth embodiment, and FIGS. The parts corresponding to are given the same reference numerals.

In the present embodiment, metal long plates 24 and 25 each functioning as an antenna substrate of two antenna elements 15 are combined, and each metal long plate 24 and 25 is connected to the ground conductor 11 of the power feeding substrate 10. By soldering,
Four antenna elements 1 arranged at equal intervals on the power feeding board 10.
A circularly polarized wave antenna in which 5 is erected is constructed. Each antenna element 15 has a notch 26 formed by cutting out an antenna substrate made of a metal plate corresponding to approximately half of the long metal plate 24 or 25 in a substantially L-shaped band shape, and the notch of the antenna substrate. A through hole 27 is formed near 26. One end of the power supply line 28 is soldered to the through hole 27, and the other end of the power supply line 28 is soldered to the power supply terminal 12 of the power supply board 10. Also, FIG.
As shown in FIG. 3 (a), one metal elongated plate 24 has two notches 26 of the antenna element and a notch 2 with the lower end opened.
4a are formed, and as shown in FIG.
On the other long metal plate 25, two notches 26 of the antenna element and a notch 25a having an open upper end are formed. The circularly polarized wave antenna shown in FIG. 12 is obtained by combining these two long metal plates 24 and 25 so that the cuts 24a and 25a of the metal long plates 24 and 25 are vertically overlapped with each other in the central portion. As a material for the long metal plates 24 and 25, a metal having a small electric resistance and capable of being soldered, for example, copper, brass, or a material plated with these is suitable.

When the metal plate is used as the antenna substrate in this way, the antenna substrate with the notch 26 can be manufactured easily and inexpensively by press working or the like. Moreover, in the present embodiment, the number of antenna substrates for the four antenna elements 15 is two.
Since it has a simple structure including the long metal plates 24 and 25, the number of parts and the number of assembling steps can be reduced. In addition, it is also possible to manufacture an integrated metal member formed by forming a plurality of metal antenna substrates in a desired arrangement by die casting or the like, in which case the manufacturing cost of the circularly polarized antenna is significantly increased. It can be reduced. However, when the antenna substrate made of a metal plate is used, the height dimension is slightly higher than that when a dielectric substrate is used, because the wavelength is not shortened by the dielectric.

[0032]

The present invention is carried out in the form as described above, and has the following effects.

N (for example, 4) antenna elements are erected at equal intervals on the feeding board, and the notches of the antenna elements have a phase difference of 360 ° / N (90 ° in the case of N = 4). Since the circularly polarized wave antenna is configured to be fed with, the total length of each notch is about 1/4 of the wavelength of the resonating radio wave on the antenna substrate, and the height dimension can be significantly reduced. In particular, the vertical portion of the notch of each antenna element extends vertically and the upper end is exposed to the upper end surface of the antenna substrate, and the horizontal portion extends laterally from the lower end of the vertical portion and terminates at the closed end. When the notch is formed into a substantially L shape, the length of the vertical portion of the notch can be shortened, so that the height dimension of each antenna element can be further reduced and the height of the circularly polarized antenna can be reduced.

If the upper end surface of the antenna board is shorter than the lower end surface and the inclined end surface is continuous with the upper end surface, when the notch is excited, the upper end surface and the inclined end surface of the antenna board are formed. Since a strong electric field is generated in the antenna, the maximum radiation direction of the circularly polarized antenna shifts from the zenith direction to the low elevation angle side, which is effective when receiving radio waves from geostationary satellites on the equator in high latitude areas.

Also, approximately one half of one large substrate on the one side in the longitudinal direction and approximately half of the other side are used as the antenna substrates of two antenna elements, respectively, and the two large substrates are arranged at the central portion. If the four antenna elements are arranged upright on the power feeding board by combining them orthogonally with each other, the number of parts and the assembly can be increased as compared with the configuration in which four single antenna elements are combined. Since man-hours can be reduced,
Manufacturing cost can be reduced.

Further, a conductor layer is provided on one surface of the dielectric substrate to form an antenna substrate, and the conductor layer is formed in a notch in a band-shaped notch shape and a position across the notch on the other surface of the dielectric substrate. With the configuration including the microstrip line connected to the conductor layer, the height dimension can be further reduced by the wavelength shortening action of the dielectric, and impedance matching can be easily achieved. In this case, if the electrode layer facing the conductor layer near the upper end is provided at a position including the region facing the upper end of the notch on the other surface of the dielectric substrate, the notch with the highest electric field strength can be obtained. Since the capacitance has been increased at the upper end of the, the total length of the notch required to resonate with the radio wave of the desired frequency can be shortened, and the height reduction of the circular polarization antenna is further promoted. it can.

Further, when the metal plate is used as an antenna substrate, and the metal plate is provided with a notch formed by cutting out the metal plate in a strip shape and a power supply line connected to the metal plate in the vicinity of the notch, press working, etc. Thus, the notched antenna substrate can be easily manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a circular polarization antenna according to a first exemplary embodiment of the present invention.

FIG. 2 is an explanatory view showing the front and back of one antenna element in the first embodiment example.

FIG. 3 is an explanatory diagram showing the front and back of a power supply board according to the first embodiment.

FIG. 4 is an explanatory view showing the front and back of an antenna element according to a second embodiment example of the present invention.

FIG. 5 is an explanatory diagram showing a maximum radiation direction of an electric field on an antenna element in the second embodiment example.

FIG. 6 is a characteristic diagram showing a radiation pattern in the second embodiment example.

FIG. 7 is an explanatory view showing the front and back of the antenna element according to the third embodiment of the present invention.

FIG. 8 is a perspective view of a circular polarization antenna according to a fourth exemplary embodiment of the present invention.

FIG. 9 is an explanatory diagram showing two large substrates according to a fourth embodiment.

FIG. 10 is a perspective view of a circular polarization antenna according to a fifth exemplary embodiment of the present invention.

FIG. 11 is an explanatory diagram showing front and back surfaces of a power supply board according to a fifth embodiment.

FIG. 12 is a perspective view of a circularly polarized wave antenna according to a sixth exemplary embodiment of the present invention.

FIG. 13 is an explanatory diagram showing two large substrates in the sixth embodiment.

FIG. 14 is an explanatory diagram showing a 4-wire wound helical antenna as a conventional example.

[Explanation of symbols]

10 Power supply board 11 Ground conductor 12 power supply terminals 13,20 through hole 14,19 Microstrip line 15 Antenna element 16 Dielectric substrate 16a inclined end face 17 Conductor layer 18,26 notches 21 electrode layer 22,23 Dielectric large substrate 24,25 long metal plate (large substrate) 28 power lines

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5J021 AA03 AA04 AA10 AA12 AB05                       CA03 CA06 FA05 FA32 GA02                       HA05 HA07 JA06 JA07                 5J045 AA01 AA21 AB05 AB06 BA01                       CA04 DA06 FA01 GA03 HA03                       JA04 JA17 MA04 NA08

Claims (7)

[Claims] 1. An antenna element having a notch which is a non-conductor portion extending in a strip shape on an antenna substrate, one end of the notch is exposed to an upper end surface of the antenna substrate and the other end is a closed end, and the antenna element is provided. N (but N
Is an integer of 3 or more) and a power feeding means for exciting the notches, and each notch of the N antenna elements is fed with a phase difference of 360 ° / N. Characteristic circular polarization antenna. 2. The vertical portion according to claim 1, wherein the notch of the antenna element extends in the vertical direction and the upper end is exposed to the upper end surface of the antenna substrate, and the vertical direction extends from the lower end in the lateral direction. A circularly polarized antenna formed into a substantially L shape having a horizontal portion extending to the end and having a closed end. 3. The circularly polarized wave according to claim 1 or 2, wherein the antenna substrate has a shape in which an upper end surface is shorter than a lower end surface and an inclined end surface is continuous with the upper end surface. antenna. 4. The antenna substrate of each of the two antenna elements according to any one of claims 1 to 3, wherein approximately one half of one large substrate on one end side in the longitudinal direction and approximately half of the other end side thereof are respectively defined as two antenna substrates of the antenna element. None, and by combining the two large substrates so as to be orthogonal to each other in the central portion, the four antenna elements are arranged upright on the power feeding substrate at equal intervals. Circular polarized antenna. 5. The antenna substrate according to claim 1, wherein the antenna substrate is provided with a conductor layer on one surface of a dielectric substrate, and the notch is formed by cutting the conductor layer into a band shape. And a microstrip line formed at a position across the notch on the other surface opposite to the one surface of the dielectric substrate, and for connecting one end of the microstrip line to the conductor layer. A circular polarization antenna, comprising: a through hole formed in the dielectric substrate, wherein the conductor layer and the microstrip line are respectively connected to a ground conductor and a feeding terminal. 6. The electrode layer according to claim 5, wherein the other surface of the dielectric substrate includes a region facing the upper end of the notch, the electrode layer facing the conductor layer near the upper end. A circularly polarized antenna characterized in that 7. The antenna substrate according to claim 1, wherein the antenna substrate is made of a metal plate, and the notch is formed by cutting the metal plate into a band shape, and the notch A circularly polarized wave antenna, comprising a power supply line connected to the metal plate in the vicinity thereof, wherein the metal plate and the power supply line are respectively connected to a ground conductor and a power supply terminal.