JPH01238305A - Waveguide slot array antenna - Google Patents

Abstract

PURPOSE:To vary the radiation beam direction of a waveguide slot array antenna by loading a dielectric substance whose dielectric constant varies with the intensity of the transmitted light into a square waveguide and varying the intensity of light made incident on the dielectric substance. CONSTITUTION:A signal inputted from an input flange 4 into a square waveguide 1 is propagated in the square waveguide 1. Then the signal is radiated little by little from plural slots 2 into space. Moreover, the light incident from a light source 9 into the optical fiber 8 is made incident on the dielectric substance 7 loaded in the square waveguide 1 through the optical fiber 8 and propagated in the dielectric substance 7. With the intensity of light made incident on the dielectric substance 7 varied continuously from zero to one, the dielectric constant epsilon of the dielectric substance 7 varies continuously from epsilon1 to epsilon2. Furthermore, the guide wavelength lambdag of the signal propagated in the square waveguide 1 is varied continuously from lambdag1 to lambda2. Thus, the direction 5 of the radiation beam is changes as shown in the change 10 of the radiation beam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an array antenna used for radar or communication.

[Conventional technology]

Figure 9 shows, for example, RoE, Coff1n, F, J, Z.
Written by Ucker' Antenna Theory pa
rt 1〃, a perspective view of a conventional waveguide slot array antenna shown on page 590, and FIG. 10 is a cross-sectional view of the conventional waveguide slot array antenna. In each figure, (1) is a square. waveguide, (2) is a slot cut along the waveguide central axis of the wide surface of the rectangular waveguide), +31 is a non-reflection termination provided at one end of the rectangular waveguide, (4) is the input flange, (5) is a vector representing the direction of the radiation beam radiated into space from this waveguide slot array antenna,
(6) is the radiation beam.

Next, the operation will be explained. The signal input from the input flange (4) to the rectangular waveguide (1) is transmitted through the rectangular waveguide (1).
) propagates within. And the above signal has multiple slots (
2) It is radiated into space little by little, and the above slot (2)
The signal that is not radiated into space is absorbed by the non-reflection termination (3). Since the internal wavelength of the signal propagating in the rectangular waveguide +11 is constant within the rectangular waveguide, the phase distribution of the signal radiated into space from the slot (2) in the waveguide central axis direction is A radiation beam (6) is formed in a radiation beam direction (5) that corresponds to this phase distribution determined by the arrangement interval of (2).

[Problem to be solved by the invention]

The conventional waveguide slot array antenna is constructed as described above.Since the wavelength of the signal propagating in the rectangular waveguide (1) is constant, it is radiated into space from the plurality of slots (2). The phase distribution of the signal in the direction of the central axis of the waveguide is determined by the arrangement interval of the slots (2). The direction (5) of the radiation beam is therefore fixed.

There was a problem in that the direction (5) of this radiation beam could not be varied.

This invention was made to solve the above-mentioned problems, and an object thereof is to obtain a waveguide slot array antenna that can change the direction (5) of a radiation beam.

[Means for Solving the Problems] In the waveguide slot array antenna according to the present invention, a rectangular waveguide is entirely or partially loaded with a dielectric whose permittivity changes depending on the intensity of transmitted light.

A mechanism for making light enter the dielectric is provided in the rectangular waveguide.

[Effect]

In the waveguide slot array antenna of this invention, a dielectric material whose permittivity changes depending on the intensity of transmitted light is loaded in all or part of a rectangular waveguide, and the intensity of light incident on this dielectric material is changed. This causes the dielectric constant of the dielectric to change, and this change in dielectric constant changes the channel wavelength of the signal at the location where the dielectric is loaded, and due to this change in the channel wavelength, the signal radiated from the slot into space changes. The phase distribution of the radiation beam changes, and this change in phase distribution changes the direction of the radiation beam that is formed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a perspective view of the embodiment, and FIG. 2 is a sectional view of the embodiment.
In each figure, ill is a rectangular waveguide, (2) is a plurality of slots cut along the waveguide central axis of the wide surface of the rectangular waveguide (1)), and +3+ is the rectangular waveguide. (1) is the non-reflective termination provided at one end, (4) is the input flange, (5 is
) is a vector representing the direction of the radiation beam radiated into space from this example, (6) is the radiation beam, and (7) is the change in dielectric constant depending on the intensity of the transmitted light loaded in the rectangular waveguide (11). (8) is the rectangular waveguide ft1) e
an optical fiber (9) is connected to this optical fiber (8) and supplies light to this optical fiber (8), αG#''11. - is a vector representing the change in the value.

Next, the operation will be explained. The signal input from the input flange (4) to the rectangular waveguide (1) is transmitted through the rectangular waveguide (1).
) propagates within. And the above signal has multiple slots (
2) It is radiated into space little by little, and the above slot (2)
The signal that is not radiated into space is absorbed by the non-reflection termination (3). Further, the light incident on the optical fiber (8) from the light source (9) is incident on the dielectric material (7) loaded in the rectangular waveguide (1) through this optical fiber (8).

It propagates within this dielectric (7). The above rectangular waveguide tit
The pipe wavelength λg of the signal propagating inside the dielectric (
If the dielectric constant of 7) is C, it is given by the following equation.

Further, λ is the free space wavelength of the signal, g□ is the dielectric constant of the free space, and a is the dimension of the wide surface of the rectangular waveguide (1). The maximum value of the intensity of light incident on the dielectric (7) is set to 1, and by changing the intensity of the light output from the light source (9) to the optical fiber (8), the dielectric (
7) When the intensity of light incident on the dielectric material +71 is continuously changed from 0 to 1, the dielectric constant δ of the dielectric +71 changes continuously from 81 to 62 as shown in Figure 3. Therefore, when the intensity of the light incident on the dielectric (7) is continuously changed from 0 to 1, the internal wavelength λg of the signal propagating in the rectangular waveguide +11 becomes as shown in FIG. It changes continuously from λg1 to 2g2. The phase distribution of the signal radiated into space from the slot (2) in the direction of the center axis of the waveguide is determined by the arrangement interval of the slot (2) and the internal wavelength of the signal propagating in the rectangular waveguide (1). The direction of the radiation beam corresponding to this phase distribution (5
) to form a radiation beam (6). At this time, the tube wavelength λg changes as shown in FIG. 4 due to a change in the intensity of the light incident on the dielectric (7), so the phase distribution changes and the direction (5) of the radiation beam changes. By changing the intensity of the light incident on the dielectric (7), the direction (5) of the radiation beam is changed as shown in change value 1 of the radiation beam. It can be changed. In addition, the above rectangular waveguide (11
The position at which light is made to enter the dielectric (7) from the optical fiber (8) through the optical fiber (8) is not the end face of the rectangular waveguide tll as shown in this embodiment, but any arbitrary position of the rectangular waveguide (1). However, similar effects can be expected.

FIG. 5 is a sectional view of another embodiment of the invention.

+11 to +51 in the figure. +81 to αG are the same as in the above embodiment. (7) is a flat dielectric whose dielectric constant changes depending on the intensity of transmitted light, which is placed on the opposite side of the slot (2) in the rectangular waveguide +11. The embodiment shown in FIG. 5 also has the same effects as the above embodiment. FIG. 6 is a sectional view of a third embodiment of the present invention, in which a beam splitter (Lυ) distributes light from a light source (9) to a plurality of optical fibers (8), (7).Furthermore, FIGS. 1 and 8 are cross-sectional views of the fourth and fifth embodiments of the present invention, respectively, in which the rectangular waveguide (1) A dielectric material (7) whose dielectric constant changes depending on the intensity of a plurality of transmitted lights is loaded in the position where the slot (2) is not cut.

Light is made to enter each of the dielectrics (7) from an optical fiber (8).The same effects as in the above embodiment can be expected with these configurations as well.

Further, in these embodiments, the light source (9) may be of any type as long as it can vary the intensity of the light it outputs, and its type and configuration are not particularly limited, such as a laser diode, LED, or incandescent light bulb. Furthermore, in the above embodiment, light is incident on the dielectric (7) through the optical fiber (8), but a small light source such as a laser diode or LED is embedded in the rectangular waveguide (1) to direct light from the light source. The light may be made to directly enter the dielectric (7). Furthermore, the slot (2) in the above embodiment is a slot cut along the waveguide center axis of the wide surface of the rectangular waveguide +11, but the slot (2) is a slot cut along the waveguide central axis of the wide surface of the rectangular waveguide (1). Slots cut perpendicular to the center axis of the tube, slots cut diagonally to the center axis of the waveguide,
Similar effects can also be expected by using it as a throttle slot (2) cut into the narrow side of a rectangular waveguide.

(Effects of the Invention) As described above, according to the present invention, a dielectric whose permittivity changes depending on the intensity of transmitted light is loaded into a rectangular waveguide, and the mechanism for making light incident on this dielectric is used in the waveguide. By changing the intensity of light incident on the dielectric material provided in the tube, there is an effect that the direction of the radiation beam of the waveguide slot array antenna can be varied.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a waveguide slot array antenna according to an embodiment of the present invention, FIG. 2 is a sectional view of a waveguide slot array antenna according to an embodiment of the invention, and FIG. 3 is a diagram showing the intensity of light. FIG. 4 is a diagram showing the relationship between the intensity of light and the wavelength within the tube, and FIG. 5 is a cross-sectional view of another embodiment of the present invention. 6 is a sectional view of a third embodiment of the invention, FIG. 7 is a sectional view of a fourth embodiment of the invention, FIG. 8 is a sectional view of a fifth embodiment of the invention, and FIG. 9 is a sectional view of a fifth embodiment of the invention. 1 is a perspective view of a conventional waveguide slot array antenna, and FIG. 1 is a sectional view of the conventional waveguide slot array antenna. (1> is the rectangular waveguide, (2) is the thrower), +3) is the non-reflective termination, (4) is the input 7 range, (5) is the vector representing the direction of the radiation beam, (6) is the radiation beam, (7) is a dielectric, (8) is an optical fiber, (9) is a light source, α is a vector representing a change in the radiation beam, and αυ is a beam splitter. In addition, in FIG. 1, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A waveguide slot array antenna consists of a waveguide with multiple slots cut into one wall of the rectangular waveguide, and a non-reflection termination provided at one end of the waveguide. A waveguide slot array is created by loading a dielectric whose index changes into the waveguide, providing a mechanism in the waveguide to make light incident on the dielectric, and changing the intensity of the light incident on the dielectric. A waveguide slot array antenna characterized in that the direction of a radiation beam radiated into space from the antenna can be varied.