JPH0355904A - Plane antenna - Google Patents

Abstract

PURPOSE:To attain higher degree of freedom in the wiring design of a feeder line and to reduce the loss of the feeding line by using two inductive supports and two conductive supports so as to form a radiation element part and a feeding part separately. CONSTITUTION:On the upper face of a plane antenna 5, plural radiation elements, that is, 16 circular patches 1 made of a conductor in this case are formed on a board or the like made of a dielectric material or the like. As shown in figure, a feeding line 2 is formed on the same board to connect two each of the circular patches 1. Moreover, a slot 3 feeding a feeding line 2 is formed on other board. Furthermore, other conductor 4 is formed other board to be coupled electromagnetically with the slot 3. The boards 7, 9, 10 form tri-plate structure and the conductors 8, 11 are of the same potential, then the radiation loss attending the feeding of the conductor line 4 is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention relates to a flat antenna used for satellite broadcasting, etc., in which a radiation element layer and a feed layer are formed as separate layers.

(Prior Art) Recently, flat antennas have been attracting attention as antennas that can easily receive satellite broadcasting in general homes.

FIG. 4 shows a conventionally used planar antenna.

A top view of the planar antenna is shown in FIG. FIG. 5B shows a sectional view taken along lines A and B in FIG. As shown in Figure (a), the planar antenna has a plurality of radiating elements 20 formed of conductors or the like on the upper surface of a dielectric substrate, etc., and a feeder for feeding each of the guiding radiating elements 20. The electric wire is also a conductor, etc., and the radiating element 2
It is formed on the same plane as 0. Further, as shown in FIG. 2B, a ground conductor 22 is formed of a conductor or the like on the lower surface of the dielectric substrate, and serves as a ground.

Power is fed from a feed point 23, and the feed line includes a feed line 24 extending from this feed point 23 to the radiating element 20 for feeding power, and a feed line 25 connecting the radiating elements 20.
It can be divided into As can be seen from Figure (a), the feed line 24 must be formed from the feed point 23 to the vicinity of the radiating element 20, so this feed line 24 takes up a considerable amount of space on the dielectric substrate, which increases the freedom of wiring design. will be limited.

(Problems to be Solved by the Invention) As described above, in the conventional planar antenna, there is no flexibility in wiring the feed line, making it difficult to design the radiating element and the wiring. Furthermore, since the feeding line is long, feeding loss increases and antenna efficiency decreases. Radiation from this feed line may affect the directivity of the radiating element. However, since the power feeding section and the radiating element section are integrally formed, there is a drawback that the substrate thickness cannot be increased so much that a frequency band cannot be obtained very much.

Therefore, in view of the above points, it is an object of the present invention to provide a highly efficient planar antenna in which the feeding section and the radiating element section are formed separately to reduce the loss of the feeding line.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a first radiating element having a plurality of radiating elements and a feeding line for feeding the plurality of radiating elements. a first conductive support formed with a slot for electromagnetically coupling to the feed line; and a conductor line for electromagnetically coupling to the slot. The second i4 conductive support and the second conductive support are stacked one after another.

Further, a first dielectric support body on which a plurality of radiating elements and a feed line for feeding power to the plurality of radiating elements are formed;
a first conductor plate on which a slot is formed for electromagnetically coupling to the feed line; a second dielectric support on which a conductor line is formed for electromagnetically coupling to the slot; , and the second conductive plate are stacked one after another with dielectric layers interposed therebetween.

The other is a first dielectric substrate on which a plurality of radiating elements and a feed line for feeding power to the plurality of radiating elements are formed, and a conductor is formed on one side, and an electromagnetic field is provided to the feed line. a second dielectric substrate formed with a slot for coupling to the slot; a third dielectric substrate formed with a conductor line for electromagnetically coupling to the slot; and a third dielectric substrate formed with a conductor on one side. and a fourth dielectric substrate are stacked one after another.

Still another is a first dielectric film on which a plurality of radiating elements and a feed line for feeding power to the plurality of radiating elements are formed, a conductor formed on one side, and a first dielectric film formed with a conductor on one side, and with respect to the feed line. A second dielectric film formed with a slot for electromagnetic coupling, a third dielectric film formed with a conductor line for electromagnetic coupling to the slot, and a conductor on one side. and a fourth dielectric film formed thereon are stacked one after another with dielectric layers interposed therebetween.

(Function) The conductor line formed on the second dielectric support by the conductor of the first conductive support and the conductor of the second conductive support has an electromagnetically shielded triplate structure. Therefore, radiation loss and conductor loss can be reduced. Further, the radiation element portion includes a first dielectric support, a first conductive support, a first conductive support, a second dielectric support, and a second conductive support. Since the power feeding parts are formed separately, the degree of freedom in wiring the power feeding line increases.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing one configuration of a planar antenna which is an embodiment of the present invention. The figure shows the planar antenna 5.
FIG. A plurality of radiating elements, in this case 16 circular patches 1 made of a conductor, are formed on a substrate made of a dielectric material or the like. As shown in the figure, a power supply line 2 is formed on the same substrate, and two circular patches 1 are connected to each other.

Furthermore, a slot 3 for feeding power to this feed line 2 is provided.
Formed on a separate substrate. Further, a conductor 4 for electromagnetically coupling to the slot 3 is formed on another substrate. The planar antenna 5 is constructed by sequentially stacking these substrates.

Here, the structure of each substrate will be explained in more detail using FIG. 2. FIG. 2 is an enlarged view of the portion a in FIG. 1. Figure (a) is a top view, and figure (b) is a top view.
) is a sectional view taken along line AB in FIG. As described above, the circular patches 1 are connected by the feed line 2. A slot 3 for supplying power to the power supply line 2 and a conductor 4 for supplying power to the slot 3 are formed on separate substrates. As shown in FIG. 2B, two circular batches 1 made of a conductor or the like and a power supply line 2 are formed on a substrate 6 made of a dielectric or the like by etching, printing, or the like. Further, the substrate 7 below it is similarly formed of a material such as a dielectric, and a conductor is formed on the entire surface of the substrate 7, and the slot 3 portion is removed by etching or the like. Further, the substrate 9 underneath is also made of a material such as a dielectric, and has a conductor line 4 formed on its upper surface for electromagnetically coupling to the slot 3. The substrate 10 underneath is also made of a material such as a dielectric, and a conductor is formed on the entire upper surface. These substrates are stacked at certain intervals. Note that this interval may not be constant. In addition, even if they are directly stacked without any spacing, they operate as a planar antenna. In this case, it can be manufactured thinner.

In FIG. 2(b), the substrates 7, 9, and 10 constitute a tribrate structure, and since the conductors 8 and 11 have the same potential, radiation loss due to the power feeding of the conductor line 4 can be suppressed. I can do it. Therefore, the radiation efficiency of the above-described planar antenna can be maintained high. In addition, this efficient power supply can be coupled to the slot 3 in that state, and this can be connected to the power supply line 2.
The circular patch 1 can be finally supplied with power. With this configuration, it is possible to configure the radiating element layer on the substrate 6 and the feeding layer on the substrates 7, 9 and 10 separately, which is difficult to do with the conventional integrated radiating element layer and feeding layer due to the effect of feeding loss. The frequency band can be varied by simply changing the distance between the substrates 7 and 10. In the above description, the substrate was used as an example, but a dielectric film that is light and thin and can be manufactured may be used as a substitute for the substrate. By tournament-feeding two or four radiating elements in this way, a multi-element planar antenna can be constructed.

Next, regarding the present invention, a planar antenna in which the circular polarization axial ratio characteristic is widened and the beam is tilted will be explained. Third
Figure (a) shows a one-dimensional four-element array in the Y direction on the X-Y plane (
FIG. 3(b) shows a one-dimensional four-element array in the Y direction on the Z-Y plane. The circularly polarized wave circular patch 12 provided with a perturbation element is configured so that the plane of polarization is spatially rotated by 90 degrees between #1 and #2, and between #3 and #4, and the phase is set using the slot 13 with the line lengths being equal. The feeder lines 14 are wired so that they are in phase when viewed from above. The structure of the feeder circuit layer below slot 13 is the same as that shown in FIG.

In the above configuration, without producing grating lobes,
Then, find the element spacing d such that the delay p in the phase of the arriving radio wave from the angle θ is equal to 1/4 of the wavelength of the desired frequency (that is, the phase difference is 90 degrees), and let the phase of #1 be the standard 0 degrees. , #2
The phase of #3 is 190 degrees from g, and the phase of #3 is -18 degrees from 2I.
The phase of #4 at 0 degrees is -270 degrees from 3g. Thereby, the beam can be tilted in the θ direction.

In addition, the polarization planes of #1 and #2 and #3 and #4 are spatially rotated by 90 degrees, and the phase difference is -90 degrees, so the circular polarization axial ratio characteristics as an array can be improved over a wide band. can be made into

By arranging the four-element array described above two-dimensionally as a sub-array and feeding it with tournament power, a beam-tilt type broadband circularly polarized multi-element array antenna can be constructed.

In the conventional example, in order to increase the aperture efficiency in order to obtain the maximum gain, the element spacing was narrowed, and the area for wiring the feed line was also narrowed, reducing the degree of freedom in wiring design, but the present invention In the embodiment, since the radiating element circuit layer and the feeder circuit layer are not on the same plane, the area for wiring the feeder line can be increased, and the degree of freedom in wiring design is increased.

Since the triplate line used in the present invention has a shielding structure, there is theoretically no radiation loss, and if it is configured with an air layer, dielectric loss can be kept small.

Further, since there is no radiation loss, the conductor loss can be reduced by making the line width wider to some extent and setting the impedance to be lower. Therefore, it is possible to provide a feed line with low loss overall. Therefore, with the multi-element array antenna according to the present invention, even if a large number of elements are arranged in order to obtain high gain and the feed line becomes long, the feed loss can be kept smaller than in the conventional example. It can be an antenna.

Since the frequency band of the radiating element depends on the height between the radiating element and the ground conductor, the frequency band can be widened by increasing the substrate thickness, and the frequency band can be narrowed by decreasing the substrate thickness. can. In the present invention, since the radiating element layer and the feeding layer can be configured separately, the height of the radiating element and the ground conductor in the radiating element layer is not limited to optimization of feeding loss as in the conventional example. , the desired frequency band can be obtained.

In the triplate structure of the feed layer, there is no radiation loss due to the shielding structure, so there is no radiation from the feed line, and the directivity of the radiating element is not affected.

The present invention has more layers than the conventional example, so the number of parts is increased, but it can be realized at low cost by using a dielectric film or the like that does not have very good high frequency characteristics.

Note that the present invention is not limited to the above embodiments,
Vehicles can be modified in various ways without departing from the gist of the concept.

For example, the substrates 7 and 10 shown in FIG. 2 may be formed of metal plates or the like.

Further, although the circular patch 1 is used as the radiating element in this embodiment, other elements such as a rectangular patch may be used.

In addition, in this embodiment, the explanation has been made on the assumption that an interval is provided between the radiation element layer and the power supply layer, and an air layer is used as a dielectric layer in this interval, but instead, a foam sheet with a low dielectric constant, etc. A dielectric material of

[Effects of the Invention] As detailed above, according to the present invention, the radiating element section and the feeding section are formed separately using two dielectric supports and two conductive supports. Therefore, there is a wide degree of freedom in the wiring design of the feeder line, and the loss in the feeder line can be reduced. Furthermore, since there is almost no radiation from the feed line, a highly efficient planar antenna can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of the present invention, and FIG. 3 is a diagram showing a beam tilt of the planar antenna of the present invention. FIG. 4 is a diagram showing a conventional example.

Claims (4)

[Claims] (1) A first dielectric support in which a plurality of radiating elements and a feed line for feeding the plurality of radiating elements are formed, and a slot for electromagnetically coupling to the feed line. a first conductive support formed with a conductive support, a second dielectric support formed with a conductor line for electromagnetically coupling to the slot, and a second conductive support, stacked one after another. A flat antenna characterized by: (2) A first dielectric support in which a plurality of radiating elements and a feed line for feeding the plurality of radiating elements are formed, and a slot for electromagnetically coupling to the feed line. A first conductive plate with a conductive layer formed on the conductive plate, a second dielectric support on which a conductive line for electromagnetically coupling to the slot is formed, and a second conductive plate are connected through a dielectric layer, respectively. A planar antenna characterized by being stacked one after the other. (3) a first dielectric substrate on which a plurality of radiating elements and a feed line for feeding power to the plurality of radiating elements are formed; a second dielectric substrate formed with a slot for coupling; a third dielectric substrate formed with a conductor line for electromagnetically coupling to the slot; and a third dielectric substrate formed with a conductor on one side. A planar antenna characterized in that a fourth dielectric substrate is stacked one after another. (4) A first dielectric film on which a plurality of radiating elements and a feed line for feeding power to the plurality of radiating elements are formed, a conductor formed on one side, and an electromagnetic field for the feed line. a second dielectric film formed with a slot for coupling; a third dielectric film formed with a conductor line for electromagnetic coupling to the slot; and a third dielectric film formed with a conductor on one side. and a fourth dielectric film are sequentially stacked with dielectric layers interposed therebetween.