JP3517021B2 - Dual-polarized planar antenna - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vertically polarized wave and a horizontally polarized wave,
Alternatively, the present invention relates to a dual polarized planar antenna that shares both right-handed circular polarization and left-handed circular polarization.

[0002]

2. Description of the Related Art FIG. 6 is an exploded perspective view of a conventional orthogonal polarization plane antenna. As shown in FIG. 6, a conventional orthogonal polarization planar antenna has a first feed substrate 2, a conductor plate 3, a second feed substrate 4 for horizontal polarization, and a radiation circuit plate 5 on a conductor plate 1 in this order. The dielectrics 6 to 9 are stacked. The first feeding board 2 is provided with a first feeding line 11 from one side toward the center, and the conductor plate 3 is provided with a slot 12 so as to be orthogonal to the feeding line 11. In addition, the second power supply board 4 is provided with a second power supply line 13 from the side toward the center so as to be parallel to the slot 12.
Is provided. Then, the conductor plate 14 is laminated on the upper surface of the radiating circuit board 5, and, for example, a rectangular radiating element 15 is formed in the center thereof. In the above-mentioned orthogonal polarization plane antenna, the first feed line 11 operates for vertical polarization and the second feed line 13 operates for horizontal polarization.

FIG. 7 is a top view of the above-mentioned planar antenna, showing the feeder lines 11 and 13 for the radiating element 15 and the slot 12.
Shows the arrangement relationship of. Since the second feed line 13 is arranged between the slot 12 and the radiating element 15 as described above, the coupling between the slot 12 and the radiating element 15 is affected. Therefore, conventionally, the slot 12 is offset from the center of the radiating element 15 in the direction of the first feed line 11 as shown in FIG.

In the orthogonal polarization planar antenna configured as described above, when a current is fed from the second feed line 13, the radiating element 15 is coupled with the magnetic field around the feed line 13 and is directed in the direction of the feed line 13. It radiates a linearly polarized wave with a polarization component.
Further, when a current is fed from the first feeding line 11, the slot 12 is excited and coupled with the radiating element 15, and the radiating element 15 radiates a linearly polarized wave having a polarization component in the direction of the feeding line 11. Therefore, vertical polarization and horizontal polarization can be transmitted or received at the same time.

[0005]

FIG. 8 shows the current distribution on the radiating element 15 when the radiating element 15 in the planar antenna is excited in the fundamental mode. The current distribution of the radiating element 15 has a minimum current at both ends and a maximum current at the center, so that the magnetic field is maximum at the center of the radiating element 15. Therefore, when the slot 12 is offset as in the conventional case, the radiating element 15 and the slot 1 are
There is a problem that the cross polarization characteristic is deteriorated because the coupling with 2 becomes weak and the structure becomes asymmetric.

The present invention has been made in view of the above circumstances, and it is possible to strengthen the coupling between the radiating element and the slot.
It is an object of the present invention to provide a dual polarization plane antenna having excellent cross polarization characteristics.

[0007]

According to a first aspect of the present invention, there is provided a first conductor plate, a first feed substrate having a linear first feed line, and a slot orthogonal to the first feed line. And a second feed board having a second feed line parallel to the slot, and a radiating circuit board having a radiating element formed in the center and a conductor plate around the radiating element. In a dual-polarization plane antenna, which is formed by sequentially stacking and are separated from each other by a dielectric, the slot is provided at the center of the lower surface of the radiating element, and the second feed line is branched into two. It is characterized in that it is provided on both sides of the slot.

According to a second aspect of the present invention, in the above-mentioned plane antenna for dual polarization, the radiation element is loaded with a degenerate separation element so that circularly polarized wave can be radiated by one-point feeding. And a right-handed and left-handed circularly polarized wave are excited by the second feed line. The third invention is based on the first invention.
The invention is characterized in that a plurality of planar antennas of the invention or the second invention are arranged.

[0009]

[Action]

(First Invention) In the dual-polarization planar antenna configured as described above, when current is fed from the second feed line, the second feed line and the radiating element are coupled by the magnetic field, and the second feed line is formed. Excitation of linearly polarized wave in the direction of. Also, the first
When a current is fed to the feeding line of No. 1, the first feeding line is coupled with the radiating element via the slot, and a linearly polarized wave having a polarization component orthogonal to the second feeding line is excited.

Since the slot is arranged substantially directly under the center of the radiating element, the power input from the first feed line can be coupled at the position where the coupling is maximized, and the slot is asymmetrical in structure. It is possible to eliminate deterioration of cross polarization characteristics.

(Second invention) By loading the degenerate separation element on the radiating element, the electric field excited by the first feeding line and the electric field excited by the second feeding line are orthogonal to each other. Therefore, it is possible to excite the right-handed circularly polarized wave in one of the feeding lines and the left-handed circularly polarized wave in the other feeding line.

(Third Invention) By arranging a plurality of planar antennas according to the first invention or the second invention, a total gain of the antenna can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) The basic structure of the present invention will be described with reference to FIGS.

FIG. 1 is an exploded perspective view showing the basic structure of a linearly polarized planar antenna according to the present invention. As shown in FIG. 1, a first feeding board 2, a conducting board 3, a second feeding board 4, and a radiation circuit board 5 are sequentially laminated on a conductor plate 1 with dielectrics 6 to 9 interposed therebetween. The conductor plates 1 and 3 are made of, for example, aluminum or copper, and the feeding substrates 2 and 4 and the radiation circuit plate 5 are made of, for example, an insulating film substrate (PET). As the dielectrics 6 to 9, for example, foamed sheets of polyethylene or the like are used. The first power supply board 2
Is provided with a first feed line 11 toward the center from the center of one side, and the conductor plate 3 is provided with a slot 12 so as to be orthogonal to the feed line 11. Further, the second power supply board 4 is provided with a second power supply line 21 in parallel with the slot 12. The feeding line 21 has a shape in which the tip portion is bifurcated. Then, a conductor plate 14 made of aluminum or copper is laminated on the upper surface of the radiating circuit board 5, and a rectangular radiating element 15 is formed in the central portion thereof. In the case of the above-described linearly polarized plane antenna, the first feed line 11 is used for vertically polarized waves and the second feed line 2 is used.
1 works for horizontal polarization.

FIG. 2 is a top view of the above dual-polarized plane antenna and shows the positional relationship of the feed lines 11 and 21 and the slot 12 with respect to the radiating element 15. Slot 12
Are provided so as to correspond to substantially the center of the radiating element 15 as shown in FIG. Further, the feed line 11 for vertically polarized waves is provided so as to extend so that the tip end thereof is orthogonal to the slot 12. And the horizontal polarization feed line 2
1 is arranged so as to be orthogonal to the feed line 11, and
It is divided into two so as not to affect the coupling between the slot 12 and the radiating element 15, and the branched portions are located on both sides of the slot 12.

In the dual polarization plane antenna configured as described above, when a current is fed from the second feed line 21, the feed line 21 and the radiating element 15 are coupled by a magnetic field,
A linearly polarized wave is excited in the direction of the power feeding line 21. Also, the first
When the power is fed to the power feeding line 11 of (1), it is coupled with the radiating element 15 through the slot 12 and excites a linearly polarized wave having a polarization component orthogonal to the second power feeding line 21.

In this case, the slot 12 has a radiating element 15
Since the electric power input from the power feeding line 11 is almost directly below the center, the electric power input from the electric power feeding line 11 can be coupled at a position where the coupling is maximum. Further, since the slot 12 is located at the center of the radiating element 15, it is possible to eliminate the deterioration of the cross polarization characteristic due to the asymmetry of the structure.

FIG. 3 is an exploded perspective view showing a concrete example of linearly polarized waves according to the present invention, which is formed by combining a plurality of the basic antenna elements shown in FIG.
That is, a plurality of vertical polarization feed lines 11, slots 12, horizontal polarization feed lines 21, and radiation elements are provided on the first power feed board 2, the conductor plate 3, the second power feed board 4, and the radiation circuit board 5, respectively. 15 are provided correspondingly to configure a linearly polarized plane antenna composed of a plurality of antenna elements.

By forming a plurality of antenna elements as described above, the total gain of the antenna can be improved. (Second Embodiment) Next, a case where the present invention is applied to a circularly polarized plane antenna will be described.

FIG. 4 is an exploded perspective view showing the basic structure of the dual-polarization planar antenna according to the present invention when it is a circularly polarized planar antenna. In FIG. 4, reference numeral 22 denotes a degenerate separation element 23 such as a notch at the corner of the linearly polarized wave excitation element.
It is a radiating element that loads a and 23b and radiates circularly polarized waves by single-point feeding. Others have the same configuration as that of the linearly polarized plane antenna shown in FIG. 1, and thus the same reference numerals as those in FIG. 1 are given and detailed description thereof is omitted. In the above-mentioned circularly polarized plane antenna, the feed lines 11 and 21 act as feed lines for right-handed or left-handed circularly polarized waves.

That is, the degenerate separation element 2 of the radiating element 22.
Since the electric field excited by the feed line 11 and the electric field excited by the feed line 21 are orthogonal to 3a and 23b,
A right-handed circularly polarized wave can be excited by one of the feeding lines, and a left-handed circularly polarized wave can be excited by the other feeding line.

For example, when the radiating element 22 is constructed as shown in FIG. 4, the feed line 11 is left-handed circularly polarized wave, and the feed line 2 is
1 can excite the right-handed polarized wave. Further, when the degenerate separation elements 23a and 23b of the radiating element 22 are loaded in other corners different from those in FIG. 4, the feed line 11 is for right-handed polarization and the feed line 21 is for left-handed polarization. Acts as.

As described above, it is possible to receive or transmit both right-handed and left-handed circularly polarized waves by merely changing the radiating element in the linearly polarized plane antenna to the circularly polarized radiating element 22.

FIG. 5 is an exploded perspective view showing a concrete embodiment of the circularly polarized plane antenna according to the present invention, which is formed by combining a plurality of the basic antenna elements shown in FIG.

That is, the first power supply board 2, the conductor plate 3,
A circularly polarized planar antenna including a plurality of antenna elements, in which a plurality of feeder lines 11, a slot 12, a feeder line 21 and a radiating element 22 are provided on the second feeding board 4 and the radiating circuit board 5 so as to correspond to each other. Are configured.

In the circularly polarized plane antenna configured as described above, the slot 12 and the feed lines 11 and 21 have the same structure as in the case of linearly polarized waves, and the radiating element is changed to a circularly polarized element. It is possible to receive or transmit both right-handed and left-handed circularly polarized waves.

Further, similarly to the linearly polarized planar antenna shown in the first embodiment, the slot 12 is arranged almost directly under the center of the radiating element 22, so that the electric power input from the feed line 11 is maximally coupled. It is possible to couple at different positions, and it is possible to eliminate the deterioration of the cross polarization characteristic due to the asymmetry of the structure.

In each of the above-described embodiments, the case where the rectangular microstrip antenna is used as the radiating element 15 has been described, but a circular microstrip antenna can also be implemented in the same manner as in the above-mentioned embodiments. The same effect can be obtained. Even when a circular radiating element is used, a concave or convex degenerate separation element can be formed to form a circularly polarized plane antenna that shares right-handed circular polarization and left-handed circular polarization. .

[0029]

As described in detail above, according to the present invention, the slot is arranged immediately below the radiating element, and the second feed line located between the slot and the radiating element is branched into two slots. Since they are located on both sides of, the electric power input from the first feed line can be coupled at the position where the magnetic field is maximum, and the deterioration of the cross polarization characteristics can be prevented.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a basic configuration when the present invention is used as a linearly polarized plane antenna.

FIG. 2 is a plan view of the linearly polarized planar antenna shown in FIG.

FIG. 3 is an exploded perspective view showing a specific embodiment when the present invention is used as a linearly polarized plane antenna.

FIG. 4 is an exploded perspective view showing a basic configuration when the present invention is used as a circularly polarized plane antenna.

FIG. 5 is an exploded perspective view showing a specific embodiment when the present invention is used as a circularly polarized plane antenna.

FIG. 6 is an exploded perspective view of a conventional orthogonal polarization plane antenna.

7 is a plan view of the orthogonal polarization plane antenna in FIG.

FIG. 8 is a diagram showing a current distribution on a radiating element in an orthogonal polarization planar antenna.

[Explanation of symbols]

1 conductor plate 2 First power supply board 3 conductor plate 4 Second power supply board 5 Radiation circuit board 6-9 dielectric 11 First feeder line 12 slots 14 Conductor plate 21 Second feeding line 22 Radiating element 23a, 23b Degenerate separation element

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Waka Iichi Saitama Prefecture Omiya City 1406 Hasunuma Yagi Antenna Co., Ltd. Omiya Factory (56) References JP 59-4206 (JP, A) JP 64 -39102 (JP, A) JP-A-5-67912 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01Q 21/24 H01Q 13/08

Claims (3)

(57) [Claims] 1. A first conductor plate, a first power feed substrate on which a linear first power feed line is formed, a second conductor plate having a slot orthogonal to the first power feed line, and A second feeding board having a second feeding line parallel to the slot and a radiating circuit board having a radiating element formed in the center and a conductor plate around the radiating element are sequentially isolated from each other by a dielectric. In the dual-polarization planar antenna formed by stacking the slots, the slot is provided so as to be positioned at the center of the lower surface of the radiating element, and the second feed line is branched so as to be positioned at both sides of the slot. A dual-polarization planar antenna characterized in that 2. A radiating element is loaded with a degenerate separation element so that circularly polarized waves can be radiated by one-point feeding, and right-handed and left-handed circularly-polarized waves are provided in the first feeding line and the second feeding line. The dual-polarization planar antenna according to claim 1, which is excited. 3. A polarization dual-purpose plane antenna comprising a plurality of the plane antennas according to claim 1 or 2.