JPH0661735A - Planar antenna - Google Patents

Abstract

PURPOSE:To provide a planar array antenna configuration in which a level of a side lobe is reduced and an excellent antenna characteristic is obtained. CONSTITUTION:Radiation elements 5 each comprising a couple of slots are stamped from a radiation circuit plate 3 at an interval of 0.79lambda0 longitudinally and laterally. A feeder circuit plate 2 is made of a flexible printed circuit board and feeder probes 3 are formed on the printed circuit board at an interval of 0.81lambda0 longitudinally and laterally. Thus, the element interval of the radiation elements 5 and the element interval of the feeder probes 6 are differentiated in this way and the deviation of the feeder probes corresponding to the radiation elements is increased from the antenna center toward its circumferential part. Thus, the radiation power of the radiation elements 5 is decreased from the center of the antenna toward the circumferential part thereby reducing the level of a 1st side lobe.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a planar antenna.

[0002]

2. Description of the Related Art As a plane antenna for receiving radio waves from a broadcasting satellite or a communication satellite, a radiating circuit board having a plurality of radiating elements is formed in order to achieve high efficiency and wide band.
An array antenna having a tri-plate structure has been developed in which a feeding circuit plate that feeds electric power by electromagnetically contacting the radiating element in a non-contact manner is stacked on a ground conductor plate via a support plate that also serves as a dielectric layer. ing.

[0003]

By the way, since the above-mentioned array antenna generates a relatively high side lobe, unnecessary radio waves are easily received when other satellites adjacent to the satellite intended for reception are close to each other, resulting in interference. There was a problem in that The present invention has been made in view of the above problems, and an object of the present invention is to provide a planar antenna having an array antenna configuration in which the side lobe level is reduced and good antenna characteristics are obtained.

[0004]

In order to achieve the above-mentioned object, the present invention provides a support plate made of a resin foam for the ground conductor layer, the feeding circuit layer, and the radiation circuit layer, each of which also serves as a dielectric layer. In the planar antenna in which the radiating element of the radiating circuit layer and the feeding probe added to the feeding line of the feeding circuit layer are electromagnetically coupled, the radiating element of the radiating circuit layer and The distance between the elements of the feeding probe added to the electric wire is made different, and the deviation of the positional relationship between the radiating element and the corresponding feeding probe is increased from the central portion of the antenna to the peripheral portion.

[0005]

According to the structure of the present invention, the radiated power gradually decreases from the central portion of the antenna toward the peripheral portion,
Since the element spacing of the radiating element of the radiating circuit layer and the element spacing of the feeding probe added to the feeding line are different, as the electromagnetic coupling between the radiating element and the feeding probe goes from the central part of the antenna to the peripheral part. As a result, the radiation power of the peripheral portion becomes smaller and the level of the side lobe can be reduced.

[0006]

EXAMPLES The present invention will be described below with reference to examples. (Embodiment 1) As shown in FIGS. 1 and 2, the planar antenna of this embodiment is an antenna that excites a linearly polarized wave, in which a ground conductor plate 1 forming a ground conductor layer from below and a feeding circuit layer are formed. The power supply circuit board 2 and the radiation circuit board 3 forming the radiation circuit layer are sequentially laminated with the dielectric layer 4 made of resin foam interposed therebetween as shown in FIG.

As the radiating circuit board 3, an aluminum plate having a thickness of 0.5 mm is used, and the radiating element 5 composed of a pair of slots is formed on the aluminum plate.
Are vertically and horizontally punched at intervals of 0.79λ ₀ . On the other hand, the power supply circuit board 2 is formed of a flexible printed circuit board, and is formed by etching a power supply circuit including a power supply line having a power supply probe 6 electromagnetically coupled to each radiating element 5 of the radiating circuit board 3. The element spacing of each feeding probe 6 is different from the spacing of the radiating element 5, for example, 0.81λ ₀ and is formed vertically and horizontally.

In other words, as shown in FIG. 3 (a), the distance between the radiating elements 5 and the distance between the feeding probes 5 are the same in the prior art, but in the planar antenna of the present invention, the distance is different as shown in FIG. 3 (b). I am doing it. Therefore, if the positional deviation between the radiating element 5 and the feeding probe 6 is minimized in the central portion of the antenna, the positional deviation increases from the central portion to the peripheral portion.

The ground conductor plate 1 arranged below the feeding circuit plate 2 is formed of a metal plate such as aluminum. Thus, in the planar antenna of the present embodiment configured as described above, the radiated power at the radiating element 5 becomes smaller from the central portion of the antenna to the peripheral portion thereof, which reduces the level of the first side lobe to that of the conventional example. 0.5 dB compared
It was possible to reduce the above.

Although the present embodiment excites linearly polarized waves, a pattern having a polarization conversion function such as meander line and a dielectric layer are sequentially laminated on the radiation circuit board 3. It is also possible to construct a circularly polarized antenna with reduced side lobes. (Embodiment 2) In this embodiment, as shown in FIG. 4, the radiation circuit board 3 using an aluminum plate having a thickness of 0.5 mm has an aperture for exciting a circularly polarized wave 0.79λ _{0 in the} vertical and horizontal directions as in the first embodiment.
In this embodiment, the feeding probes 6 are formed by punching at intervals, and the feeding probes 6 are vertically and horizontally formed at intervals of 0.81λ _{0 on} the feeding circuit board 2 made of a flexible printed circuit board by etching. Other configurations are the same as those in the first embodiment. That is, the positional deviation between the radiating element 5 and the feeding probe 6 is minimized in the central portion of the antenna, and the positional deviation is increased from the central portion to the peripheral portion. FIG. 5A shows a conventional example in which the spacing between the radiating elements 5 each having an aperture that excites a circularly polarized wave is the same as the spacing between the feeding probes 5, and FIG. 5A shows the radiating element 5 as described above. The present embodiment is shown in which the interval of 1 is different from the interval of the power supply probe 5.

Thus, also in this embodiment, the side lobes can be reduced as in the first embodiment. Although an aluminum plate is used as the radiation circuit board 4 in each of the embodiments, a flexible printed board is used, and even if the radiation element 5 is formed on this flexible board by etching, side lobes are reduced as in each embodiment. can do.

The ratio between the element spacing of the radiating element 5 and the element spacing of the feeding probe 6 is not particularly limited to the above embodiment, and for example, the spacing between the radiating elements 5 of the radiating circuit board 3 is 0.81λ _0. The first side lobe can be similarly reduced even when the element spacing of the feeding probe 6 electromagnetically coupled to the radiating element 5 is 0.79λ ₀ . FIG. 6 shows the state of the first side lobe level in the ratio of the element spacing of each radiating element 5 and the element spacing of the feed probe 6 when the element spacing is gradually reduced in the vertical and horizontal directions. As described above, when the ratio is 1, the maximum first side lobe is developed, and the first side lobes are reduced by making the element intervals of the radiating elements 5 different from the elements of the feeding probe 6. I understand. Therefore, it is understood that the intervals of the radiating elements 5 and the elements of the feeding probe 6 may be different from each other without being limited to the intervals of the above-described embodiment.

In each of the first and second embodiments, the element spacing of the radiating element 5 and the element spacing of the feeding probe 6 are different in both vertical and horizontal directions. However, the element spacing is changed only in the vertical direction or only in the horizontal direction. However, it goes without saying that the side lobes can be reduced.

[0014]

According to the present invention, in the planar antenna configured as described above, the element spacing of the radiating elements of the radiating circuit layer,
The gap between the elements of the feeding probe added to the feeding line was made different, and the positional relationship between the radiating element and the corresponding feeding probe was increased from the center of the antenna to the periphery. The dynamic coupling weakens from the central part of the antenna to the peripheral part, so that the radiated power of the peripheral part becomes smaller, the side lobe level can be reduced, and as a result, interference is less likely to occur and the array antenna with good antenna performance There is an effect that a plane ante consisting of can be realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention that can be partially omitted.

FIG. 2 is a sectional view of the above, which can be partially omitted.

FIG. 3A is an explanatory view of element spacing in a conventional example corresponding to the first embodiment. (B) is an explanatory view of element spacing in the first embodiment.

FIG. 4 is an exploded perspective view of a second embodiment of the present invention that can be partially omitted.

FIG. 5A is a diagram illustrating an element interval of a conventional example corresponding to the first embodiment. (B) is an explanatory view of element spacing in the first embodiment.

FIG. 6 is an explanatory diagram of a relationship between an element interval and a first side lobe level.

[Explanation of symbols]

 1 Ground conductor plate 2 Feeding circuit board 3 Radiating circuit board 5 Radiating element 6 Feeding probe

Claims (1)

[Claims] 1. A ground conductor layer, a feeding circuit layer, and a radiation circuit layer are laminated by interposing a support plate made of resin foam and also serving as a dielectric layer, and the radiation element of the radiation circuit layer and the power feeding are provided. In the planar antenna in which the feeding probe added to the feed line of the circuit layer is electromagnetically coupled, the element spacing of the radiating element of the radiation circuit layer and the element spacing of the feeding probe added to the feed line are made different, and the antenna center A planar antenna characterized in that a positional relationship between a radiating element and a corresponding feeding probe is increased as it goes from a portion to a peripheral portion.