JPH01243605A - Dielectric loaded array antenna - Google Patents

Abstract

PURPOSE:To reduce the array density of unit antennas constituting an array antenna and to reduce power loss in the unit antennas and in constitution for executing feed to respective unit antennas by increasing the aperture efficiency of respective unit antennas. CONSTITUTION:The array antenna 1 is arranged on a wiring substrate 2 consisting of an electric insulating material. With providing dielectrics 5 on patches 4, the aperture efficiency and the gain are made to increase in the antenna 1. Thus, the arrangement density of the patches 4 on the wiring substrate 2 can be reduced, and the loss of consumption power in a feed line with respect to the patches 4 can be reduced, whereby whole efficiency can be improved.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an array antenna loaded with a dielectric material.

2. Description of the Related Art In recent years, so-called planar antennas have been widely used. This planar antenna has a structure in which a conductor serving as a wave source is laid on one surface of an electrically insulating substrate, and a ground conductor is arranged on the other surface. Various microstrip lines and various batch antennas are used as wave sources. When using the above batch antenna, for example, a rectangular plate-shaped metal piece (
A large number of antennas (batches) are formed on a substrate to form an array antenna, and AC voltage is supplied to these antennas via a power supply line to cause them to oscillate.

Problems to be Solved by the Invention It is known that when an array antenna using such a batch antenna performs an oscillation or reception operation, side lobes occur significantly.

An example of this is shown in FIG. 7. FIG. 7 is a graph showing directivity with circular polarization as an observation target. That is, a standard transmitting antenna that emits linearly polarized radiation waves is directly opposed to a receiving antenna whose characteristics are to be observed. 5 transmitting antennas
It is rotated around an imaginary line toward the receiving antenna. In the direction where the receiving antenna has strong directivity, the above-mentioned radiated wave is received in a state equivalent to a circularly polarized wave, and the waveform P in Fig. 7 is obtained.
1°P2. Detect high levels as shown at P3. The remaining state in Figure 7 is caused by the fact that the linearly polarized radiation waves from the transmitting antenna whose polarization direction has been rotated are received with different levels of components in mutually orthogonal directions. This shows a situation where the level of the received wave oscillates.

In the characteristics of the patch array antenna observed in such experiments, large side lobes are observed as shown in FIG. It is known that in order to prevent such side lobes, it is necessary to improve the density of patch antennas forming the array antenna. Improving the configuration density in this way can reduce sidelobes, but it requires much more precise microfabrication technology when forming patch antennas, which increases the number of man-hours8.Furthermore, the length of the feed line increases, so There is a problem in that the loss of excitation power in the line increases unnecessarily, and the efficiency of the antenna decreases significantly.

An object of the present invention is to solve the above-mentioned technical problems and provide a small and highly efficient dielectric-loaded array antenna.

Means for Solving the Problems The present invention includes an array antenna disposed on a wiring board made of an electrically insulating material, and a dielectric pickle disposed on each unit antenna constituting the array antenna. This is a dielectric-loaded array antenna with special features.

Function According to the present invention, an array antenna is arranged on a wiring board made of an electrically insulating material. By arranging a dielectric equivalent on each unit antenna constituting this array antenna, the aperture efficiency of each unit antenna is increased. As a result, the arrangement density of the unit antennas forming the array antenna can be reduced, and the power loss in the configuration for feeding power to the unit antennas and each unit antenna can be significantly reduced. Furthermore, by appropriately selecting the arrangement density of the unit antennas, the overall efficiency can be significantly improved.

Embodiment FIG. 1 is a perspective view showing the configuration of a dielectric-loaded array antenna (hereinafter abbreviated as antenna) 1 according to an embodiment of the present invention. Antenna 1 will be explained with reference to FIG. 1.
In the antenna 1 of this embodiment, a large number of patches 4 made of, for example, rectangular plate-shaped metal copper are formed on one surface 3 of a wiring board 2 made of an electrically insulating material such as a synthetic resin material. Each patch 4 has, for example, a square shape in plan view, and the mutual interval L1 is, for example, 1°6λ.
0 (λO is the excitation spatial wavelength), and the overall size of the antenna 1 is selected to be, for example, 320 mm x 320 mm. This frequency is f O(1
An experiment was conducted with excitation at >1.25 GHz. Such experimental results are the results shown in FIG. 7 referred to in the section of the prior art.

On the other hand, in view of the technical problems described in the section of the prior art, the inventor of the present invention came up with the idea of arranging the dielectric material 5 as shown by the two-dot chain line on the patch 4 shown in the first figure. As an example, such a dielectric body 5 is configured in the shape of a rectangular parallelepiped, and the lateral W
l (1,25λ0), length Di (1,25λ0), and height Hl (1,42λO), and the distance MD2 of the gap between the one surface 3 and the dielectric 5 is, for example, 0.08.
Selected by λO.

The graph of FIG. 2 shows the results of observing the frequency characteristics using such an antenna 1. Regarding the standard transmitting antenna with linear polarization described in the prior art section as the configuration for obtaining the results shown in Figure 7, the polarization direction is parallel to the vertical direction and parallel to the horizontal direction. We observed the frequency characteristics of antenna 1. Line 11 in Figure 2 is the case of vertical polarization, and line 12
is the case of horizontal leakage. As is clear from FIG. 2, the antenna 1 of this embodiment has a working frequency of 12 GHz.
The result was that the frequency band f1 to f2 can be used around . As shown in an experimental example, in the range of 1 dB drop from the peak state of radiated power, the frequency band is 0.5G.
Hz was obtained.

It is understood that such measurement results show that the frequency band is significantly expanded compared to the frequency characteristics of the standard electromagnetic horn shown in FIG.

A directivity diagram of such an antenna 1 is shown in FIG. The measurement method for obtaining Fig. 4 is described in the conventional technology section.
In this embodiment, which is similar to the configuration described as the configuration for obtaining the results in FIG. 7, side lobes such as waveforms PL and P3 shown in FIG. It is understood that directivity is realized only in

FIG. 5 is a graph showing the relative radiation power of the antenna 11 according to this embodiment. 5, the antenna 1 has the configuration shown in FIG. 1, the spacing L1 between the patches 4 is 1.19λO, the patch 4 has 16 elements, and the overall size of the antenna 1 is 12cm x 12cm (4,74λO).
X4.74λ0), and the size of the dielectric 5 is as follows: horizontal W1 is 1
．． 0λ0, length D1 is 1.0λO1 height Hl is 1.2λO
and the interval D2 was set to 0.08λ0. In FIG. 5, line 13 is the relative radiated power of the antenna 1 of this embodiment, and line 14 is the relative radiated power of the standard electromagnetic horn antenna.

The present inventor has provided an antenna 11 having the dimensions described with reference to FIG. 1 and an antenna 1 having the dimensions described above in connection with FIG.
Aperture efficiency and power were measured for both. According to this, in the configuration of 64 elements shown in FIG. 1, an aperture efficiency of 35% and a gain of 28.6 dB were obtained, and in the configuration of 16 elements, an aperture efficiency of 77.1% and a gain of 23.4 dB were obtained. These results indicate that the gain of a standard electromagnetic horn is usually 2.
Considering that it is 2°6 to 22.9 dB, it is understood that the relative radiated power is more than doubled to several times larger.

As described above, in the antenna 1 of this embodiment, by providing the dielectric material 5 on the patch 4, the aperture efficiency and gain can be significantly increased, and thereby the arrangement density of the patch 4 on the wiring board 2 can be increased. It can be significantly reduced. This allows patch 4
In this embodiment, the power consumption loss in the power supply line can be reduced by half, for example. It also means that overall efficiency can be improved.

FIG. 6 is a plan view of an antenna 1a according to another embodiment of the present invention. In the embodiment described above, the patches 4 are arranged on the wiring board 2 and the dielectric material 5 is arranged thereon, but in this embodiment, for example, a crank-shaped microstrip line 6.7 is used. I made it. The microstrip line 6 consists of a full-length crank with length 2a and height b, and there is a length λg (λg
is the line wavelength).

Further, in the microstrip line 7, a crank having a length C and a height b is arranged along the entire length, and a straight portion 9 having a length λg is also interposed between these cranks. Such a configuration including the long portion of the microstrip line 6.7 and the straight portion 8.9 is repeated at a period L1.

Microstrip line 6 shown in FIG. 6 of this embodiment.
A dielectric material is placed on the length of 7, spanning both sides. In other words, a gap of length λg is provided between each dielectric. In this example, λg=0.683
λO, b=3λg/8, a=7λg/16, c=3λg
/8, L=10λg/8, L1=18λg/8
Here, the length 11 is 11=2a+2b+c(=2λg) ・-
(1) 11=I +λg (=3λg)
...Choose as in 2).

In the antenna 11 having such a configuration, the operating frequency band is 3L/2 (L+λg
) It was verified that the improvement was doubled. It was also confirmed that results similar to those of the above-mentioned embodiments could be obtained regarding the aperture efficiency and gain.

In the antenna 11 of this embodiment, in addition to the effects of the above-described embodiments, by providing the straight portion 8.9 with a length λg, the microstrip line 6 of the antenna 11 is
．． 7 can be made relatively short, thereby making it possible to significantly reduce the phase shift that occurs as the distance from the excitation side increases during excitation, thereby making it possible to expand the usable frequency band as described above. .

Effects of the Invention As described above, according to the present invention, the aperture efficiency of each unit antenna is increased. As a result, the arrangement density of the unit antennas forming the array antenna can be reduced, and the power loss in the configuration for feeding power to the unit antennas and each unit antenna can be significantly reduced.

Furthermore, by appropriately selecting the arrangement density of the unit antennas, the overall efficiency can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the basic configuration of an antenna 1 according to an embodiment of the present invention, Fig. 2 is a graph explaining the frequency band used in this embodiment, and Fig. 3 explains the frequency characteristics of a standard electromagnetic horn. 4 is a graph showing the directivity of the antenna 1, FIG. 5 is a graph explaining the gain of the antenna 1, and FIG. 6 is a plan view showing the configuration of the antenna 11 of another embodiment of the present invention. FIG. 7 is a graph showing the directivity of a typical prior art antenna. 1...Antenna, 2...Wiring board, 4...Patch, 5...Dielectric material, 6.7...Microstrip line, 8.9...Straight line portion agent Patent attorney Nishikyo Kei Department Figure 5 11.5 12.0 I wave Rf (GH2) Procedural amendment (method)

Claims (1)

[Scope of Claims] A dielectric material comprising: an array antenna disposed on a wiring board made of an electrically insulating material; and a dielectric equivalent disposed on each unit antenna constituting the array antenna. Loaded array antenna.