JPH10190349A - Dielectric wavegudie slot antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a waveguide line by conventional stacking technology, to correspond to any antenna form and to make it superior in mass production by constituting the waveguide line with a specified dielectric waveguide and providing radiation slots for the conductor layer of the dielectric waveguide. SOLUTION: A pair of conductor layers 2 and 3 are formed on the upper/ lower faces of a dielectric substrate 1 with prescribed thickness (a) along a signal transmitting direction. Via hole conductors 4 are arranged in two columns with intervals (b) on the dielectric substrate 1 so that a pair of the conductor layers 2 and 3 are electrically connected. A section whose side is surrounded by pseudo conductor faces by the group of the via hole conductors 4 formed at intervals (c) less than 1/2 of interruption wavelength constitutes the dielectric waveguide line A constituted of a×b. Plural radiation slots 6 are formed on the conductor layer 2 formed on the upper face of the dielectric waveguide line A. Thus, the slot antenna which is superior in mass production, whose cost is low and whose reliability is high can be generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leaky wave type dielectric waveguide slot antenna mainly for microwaves and millimeter waves, in which a number of radiation slots are formed in a waveguide.

[0002]

2. Description of the Related Art Heretofore, a so-called leaky waveguide slot antenna has been known in which a large number of radiation slots are formed in a metal wall of a rectangular waveguide (having a rectangular cross section) in which a signal transmission region is surrounded by metal. Have been. This is because a slot is formed in the H plane (plane of the tube wall parallel to the magnetic field) or the E plane (plane of the tube wall parallel to the electric field) of the rectangular waveguide, and the phases of the electromagnetic waves leaking from the slots are made to match. This is an antenna whose slot position is controlled.

Further, this antenna can generate linearly polarized light or circularly polarized wave depending on the shape of the slot, and there is an antenna in which the slotted waveguide slot antennas are arranged in a plane. Such a waveguide slot antenna generally has a very small loss and thus has a high radiation efficiency and a high directivity. Therefore, it is expected to be used for a flat antenna for an automobile collision prevention radar.

[0004] Compared with a patch antenna, this waveguide slot antenna has no radiation loss and no dielectric loss because it is a closed conductor pipe, so that the transmission loss can be controlled to be extremely small. Further, the waveguide slot antenna is much more excellent in characteristics than the patch antenna, for example, strict adjustment is relatively easy due to the simple structure of the antenna itself.

[0005]

However, the waveguide slot antenna has the above advantages, but the waveguide itself has a hollow pipe-like structure, so that the pipe wall is formed of a thick conductor plate. Therefore, it is difficult to fabricate slots and connect to other waveguides, and when configuring a planar antenna, waveguides must be arranged,
The drawbacks are that it is difficult to feed these waveguides, and because the waveguide is a single conductor transmission line called a pipe, the guide wavelength is longer than the wavelength in free space and grating lobes tend to appear. Having.

As described above, the waveguide slot antenna has:
Although it is very excellent in characteristics, there are many problems due to the basic structure as described above, which hinders mass production.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, to provide a dielectric waveguide slot antenna which can be manufactured by a conventional lamination technique and which is excellent in mass productivity and can be used in various antenna shapes. Is to provide.

[0008]

The inventor of the present invention has repeatedly studied the above problems, and as a result, the upper and lower surfaces of the waveguide in the waveguide slot antenna are covered with a conductive layer.
The side surface is constituted by a dielectric waveguide formed by a group of via-hole conductors arranged in two rows at an interval of 以下 or less of a cutoff wavelength in a signal transmission direction, and a radiation slot is formed by the dielectric waveguide. By providing it on the conductor layer of the tube, it can be manufactured by using the multi-layering technology conventionally used, and can be easily connected to other waveguides, and can easily supply power to the antenna. It has been found that a highly reliable slot antenna capable of mass production can be provided.

That is, a dielectric waveguide slot antenna according to the present invention comprises: a dielectric substrate; a pair of conductor layers formed on at least upper and lower surfaces of the dielectric substrate in a line direction; A dielectric line consisting of a group of via-hole conductors electrically connected between the pair of conductor layers and arranged in two lines with an interval of 1/2 or less of a cut-off wavelength in the line direction; A radiation slot is formed in the conductor layer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view for explaining the structure of one embodiment of the dielectric waveguide slot antenna of the present invention, and is a perspective view showing only the conductors for explaining the arrangement structure of the conductors. It is. In FIG. 1, 1 is a dielectric (resin or ceramic) substrate, 2 and 3 are conductor layers, 4 is a via-hole conductor, and A is a virtual dielectric waveguide line having this structure.

According to FIG. 1, a pair of conductor layers 2 and 3 are formed on the upper and lower surfaces of a dielectric substrate 1 having a predetermined thickness a at least along a signal transmission direction.
Via-hole conductors 4 are arranged in two rows with an interval b to electrically connect the pair of conductor layers 2 and 3. A plurality of rows of via-hole conductors 4 are formed along the signal transmission direction at an interval c of 以下 or less of the cutoff wavelength.

In such a structure, the upper and lower surfaces are formed of the conductor layer 2,
3, a dielectric waveguide line A having a cross section of a × b surrounded by a pseudo conductor surface formed by a group of four via-hole conductors whose side surfaces are formed at an interval c of の or less of the cutoff wavelength is formed. You.

Since a TEM wave can propagate between the conductor layers 2 and 3 formed in parallel with an interval a, if the interval c between the via-hole conductors 4 is larger than の of the cutoff wavelength λc, an electromagnetic wave is applied to this line. Is not propagated along the pseudo waveguide made here. However, by making the via hole interval c smaller than 1/2 of the cutoff wavelength λc, the electromagnetic wave cannot propagate in the direction perpendicular to the dielectric line, but reflects and propagates only in the signal transmission direction. Thus, a pseudo waveguide is formed.

In the above dielectric waveguide structure, the distance a
If the distance b and the distance b are set to aＴＥ2b, a structure similar to a waveguide in which the TE10 having the upper and lower surfaces of the dielectric substrate as E planes (planes parallel to the electric field) propagates as a main mode is obtained. However, although it is not clear about the propagation mode of the electromagnetic wave, the pure TE10
Not considered mode. If b す る と 2a, the TE10 having the upper and lower surfaces of the dielectric substrate as H planes has a structure similar to a waveguide in which the TE10 propagates as a main mode.

According to FIG. 1, the dielectric waveguide line A
In order to strengthen the electric wall, the side wall conductor layer 5 is formed in the via hole conductor 4 on the side surface of the side surface of the via hole conductor 4 so as to be electrically connected to the via hole conductor 4.

The dielectric substrate 1 is made of an organic resin, ceramics, or a composite thereof. Many organic resins have a relatively low dielectric constant, and easily emit electromagnetic waves. Also, when using ceramics,
Although a dielectric constant is higher than that of resin, using a ceramic material having a small dielectric loss even at a high frequency has an advantage of reducing the dielectric loss.

In the dielectric waveguide slot antenna of the present invention, as shown in FIG. 1, a plurality of radiation slots 6 are formed in the conductor layer 2 formed on the upper surface of the dielectric waveguide line A.

The radiation slots 6 are formed alternately on the left and right of the line A along the signal transmission direction at an interval of λg / 2, where λg is the guide wavelength transmitted in the waveguide A. By forming the slot 6 at such a position, linearly polarized light is radiated from the slot 6 and acts as a waveguide antenna. Also, by using a dielectric having an appropriate dielectric constant as the dielectric inside the dielectric waveguide line A,
The guide wavelength can be set to be equal to or less than the wavelength of free space, and the grating lobe can be suppressed.

The dielectric waveguide slot antenna as shown in FIG. 1 can be easily manufactured by a conventional lamination technique. For example, as shown in FIG. 2, a via hole is formed in a dielectric layer 1a made of an organic resin or a ceramic sheet having a predetermined thickness, and a conductive ink is filled in the hole to form a via-hole conductor 4a. And the dielectric layer 1
The conductor layer 2 having the slot 6 is formed on the upper surface of the substrate a by a screen printing method or the like, or after the conductor layer 2 is formed, the slot 6 is formed by etching. In the same manner, the side wall conductor layer 5b and the via-hole conductor 4b on the surface of the dielectric layer 1b, the side wall conductor layer 5c on the surface of the dielectric layer 1c, and the conductor layer 3 on the back surface are laminated. Thereafter, when the dielectric layer is made of a thermosetting resin, the dielectric layer can be produced by heating and curing, and when it is a ceramic green sheet, it can be produced by laminating and firing.

FIG. 3 shows an embodiment of a dielectric waveguide antenna for radiating circularly polarized waves according to the present invention. According to FIG.
The phase of the electromagnetic wave propagating in the pipe is shifted by π / 2 by forming one side of the slots 6 alternately formed at an interval of λg / 2 with respect to the line direction of the dielectric waveguide line A into a T-shape. At the location, the vector of the emitted electric field is shifted by π / 2, resulting in circular polarization.

FIG. 4 is a plan view of an embodiment in which the dielectric waveguide antenna of the present invention is formed into an array. By feeding power from the feeding point 7 at the center of the conductor layer 2 in FIG. 4, the electromagnetic wave propagating in the left-right direction is branched into the laminated dielectric waveguide formed in the up-down direction as shown by the arrow, and Circularly polarized waves are emitted in the vertical direction.

FIG. 5 is a plan view of another embodiment in which the dielectric waveguide antenna of the present invention is formed into an array. According to FIG.
A waveguide line is formed spirally from a feeding point 7 and electromagnetic waves are propagated spirally as indicated by arrows. In this embodiment, almost all electromagnetic waves are radiated from the slots because the propagation distance of the electromagnetic waves in the waveguide line is longer than that of the embodiment of FIG. The feeding point 7 can be constituted by, for example, a monopole antenna in which a feeding via-hole conductor is inserted in the waveguide line.

As described above, the dielectric waveguide slot antenna of the present invention can be easily manufactured by the conventional laminating technique. Further, even when the antenna is a planar antenna, it is not necessary to arrange the waveguides, and the via is not required. The configuration can be easily made by dividing by the hole conductor. Also, the power supply to the antenna has an excellent advantage that it can be easily configured by inserting a via-hole conductor for power supply into the waveguide to form a monopole antenna.

[0024]

As described in detail above, the present invention can be easily manufactured by applying the conventional laminating technology.
Mass production is possible, and a low-cost and highly reliable dielectric waveguide slot antenna excellent in mass productivity that can be applied to all antenna shapes can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view for explaining one embodiment of a dielectric waveguide slot antenna of the present invention.

FIG. 2 is a diagram for explaining a method for manufacturing the dielectric waveguide slot antenna of FIG.

FIG. 3 is an embodiment of a dielectric waveguide slot antenna for circularly polarized radiation according to the present invention.

FIG. 4 is a plan view of an embodiment in which the dielectric waveguide slot antenna of the present invention is formed into an array.

FIG. 5 is a plan view of another embodiment in which the dielectric waveguide slot antenna of the present invention is formed into an array.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric substrate 2, 3 Conductive layer 4 Via hole conductor 5 Side wall conductive layer 6 Slot 7 Feeding point A Dielectric waveguide line

Claims (1)

[Claims] 1. A dielectric substrate, a pair of conductor layers formed on at least upper and lower surfaces in a line direction of the dielectric substrate, and electrically connecting the pair of conductor layers in the dielectric substrate; A dielectric line consisting of via-hole conductor groups arranged in two rows at intervals of not more than １ ／ of the cutoff wavelength in the line direction, and a radiation slot formed in the conductor layer of the dielectric line; A dielectric waveguide slot antenna, characterized in that: