JP2633404B2 - Polarizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizer which is arranged in front of an antenna and changes the inclination of the plane of polarization of electromagnetic waves.

[0002]

2. Description of the Related Art FIG.
It is a perspective view which shows the conventional polarizer shown by Ink (TRANSCOPRODUCTS INC) catalog number 80, page 79, In the figure, 1 is a horn antenna which radiates an electromagnetic wave, 2 is a thin multiple dielectric substrate, 3
a, 3b, 3c, 3d, 3e are wire grids formed on one side surface of each dielectric substrate 2 by etching or the like;
These are α1, α2, α3, α4 for each dielectric substrate 2.
The inclination is made different.

Next, the operation will be described. Now, assume that the direction of the electric field of the electromagnetic wave radiated from the horn antenna 1 is E1, the direction of the magnetic field is H1, the wire grid 3a is parallel to the magnetic field direction, and the wire grid 3b is inclined at 11.25 degrees. To a 22.5 degree slope,
The wire dots 3d are inclined at 33.75 degrees, and the wire grids 3e are inclined at 45 degrees. Thereby, the electric field direction E1 of the electromagnetic wave radiated from the horn antenna 1 is gradually deflected by the wire grids 3a to 3e, and finally becomes the E2 direction in which the electric field direction is inclined by 45 degrees. At this time, the distance S between the dielectric substrates 2 and the wire grid width d are determined so as to minimize the reflection of electromagnetic waves. It is important that each dielectric substrate 2 be made of a material having a small dielectric loss in order to increase the transmittance of electromagnetic waves, and to be sufficiently thin compared to the wavelength in order to reduce reflection. Is formed.

[0004]

Since the conventional polarizer is constructed as described above, its mechanical strength is small, and the distance S between the dielectric substrates is constant due to bending or warpage of each dielectric substrate 2. There is a problem that the reflection of the electromagnetic wave is increased and the plane of polarization does not reach the expected direction of 45 degrees. On the other hand, glass or epoxy resin (FR
When a dielectric substrate such as P) is used, there is a problem that the reflection of electromagnetic waves becomes large because the dielectric constant becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can enhance mechanical strength, suppress reflection of electromagnetic waves, and surely convert a polarization plane to a desired direction. The aim is to obtain a polarizer that can.

[0006]

SUMMARY OF THE INVENTION A polarizer according to the present invention has a horn antenna for radiating electromagnetic waves, and a plurality of antennas facing the horn antenna, each of which is arranged in parallel at a predetermined interval. A small and thick dielectric substrate is provided, and a plurality of wire grids or meander lines provided on both surfaces of the dielectric substrate are sequentially deflected in a predetermined tilt direction to electromagnetic waves radiated from the horn antenna. It was done.

[0007]

According to the polarizer of the present invention, the strength and the transmittance of electromagnetic waves are improved by thickening the dielectric substrate using a material having a small dielectric loss, and the reflection of electromagnetic waves is reduced by reducing the dielectric constant. By keeping it small and providing wire grids or meander lines on both sides of the dielectric substrate, the mechanical strength of the dielectric substrate is increased, and the distance between these can be kept substantially constant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a horn antenna, 4 is a Teflon substrate as a thick dielectric substrate having a small dielectric loss, 3
Reference numerals a, 3b, 3c, 3d, and 3e denote wire grids formed on both surfaces of the Teflon substrate 1 by etching.

Next, the operation will be described. First, the electromagnetic wave radiated from the horn antenna 1 is deflected by the wire grids 3a to 3e so that the plane of polarization is gradually inclined.
Finally, the light is radiated into the space in a tilt direction of, for example, 45 degrees. At this time, the thickness S1 of the Teflon substrate 4 and the spacing S2 between the Teflon substrates 1 are determined so as to reduce the reflection of the electromagnetic wave. Also, at this thickness of about 2 mm,
The mechanical strength of the Teflon substrate 4 is sufficient. Even if the interval S2 slightly changes due to bending or warpage, the magnitude of the reflection is hardly affected, and the thickness S1 does not obviously change. Also, regarding the dielectric loss, since the Teflon substrate 4 is used, for example, glass or epoxy resin (FRP)
And so on, and the loss can be kept small. In the thick Teflon substrate, the dielectric constant ε is about 2
Therefore, the reflection of the electromagnetic wave can be sufficiently suppressed.

In the above embodiment, the wire grids 3a to 3e are provided on each Teflon substrate 4.
As shown in FIG. 2, instead of the Teflon substrate 4, a honeycomb substrate 5 having a honeycomb structure made of a dielectric material may be used, and wire grids 3a to 3e may be provided on both surfaces thereof. In this case, the mechanical strength becomes sufficient and dielectric loss,
The dielectric constant can be reduced, which is practically advantageous.

Also, as shown in FIG.
Meander line 6 may be provided in place of a to 3e,
In this case, the polarization is circularly polarized, but the same effects as those of the above embodiment can be obtained with respect to improvements in mechanical strength, dielectric loss, reflection, and the like.

[0012]

As described above, according to the present invention, a horn antenna for radiating electromagnetic waves and a plurality of the horn antennas opposed to the horn antenna and arranged at predetermined intervals are small, and dielectric loss is small. A thick dielectric substrate is provided, and electromagnetic waves radiated from the horn antenna are sequentially deflected in a predetermined tilt direction to a plurality of wire grids or meander lines provided on both surfaces of the dielectric substrate. Therefore, there is an effect that the mechanical strength is sufficient, the transmittance of the electromagnetic wave can be improved, and the unnecessary reflection of the electromagnetic wave can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a polarizer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a polarizer according to another embodiment of the present invention.

FIG. 3 is a perspective view showing a polarizer according to still another embodiment of the present invention.

FIG. 4 is a perspective view showing a conventional polarizer.

[Explanation of symbols]

 Reference Signs List 1 horn antenna 3a wire grid 3b wire grid 3c wire grid 3d wire grid 3e wire grid 4 dielectric substrate (Teflon substrate)

Claims (1)

(57) [Claims] A horn antenna for radiating an electromagnetic wave;
A thick dielectric substrate opposed to the horn antenna and a plurality of which are arranged in parallel at predetermined intervals, each having a small dielectric loss, provided on both surfaces of the dielectric substrate, and radiated from the horn antenna; And a plurality of wire grids or meander lines for sequentially deflecting the applied electromagnetic waves in a predetermined inclination direction.