JPS58114502A - Elliptically polarized wave controller - Google Patents

Abstract

PURPOSE:To attain ease of adjustment, and to obtain small-sized and light- weighted titled controller, by re-reflecting the reflected waves refrected by a reflecting member to an output side again by means of a re-reflection member. CONSTITUTION:A reflection ring 24 is provided to the output side of a circular polarized wave generator, and plural elliptically polarized wave adjustment screws 26A-26C are provided to the input side of the generator in the orghogonal direction to an electric field of the input straight line polarized waves, and the slope of the major axis of the elliptically polarized waves is changed by changing the insertion length of the adjusting screws, and the axial ratio of the elliptically polarized wave is changed by changing the size of the ring of the reflecting rign 24, allowing to control the elliptically polarized waves. Thus, without using a large scale of controller, a small-sized and light-weighted elliptically polarized wave controller which is easy to adjust can be obtained.

Description

[Detailed Description of the Invention] Correction of distortion of the polarization ellipse of magnetic waves, polarization matching of circularly polarized waves to maximize the power supplied to circularly polarized receiving antennas, cross polarization patterns in multi-horn antennas This relates to a device that controls the axial ratio and major axis inclination of a polarization ellipse suitable for use in controlling the polarization ellipse of electromagnetic waves radiated from a horn antenna used in the microwave band, etc. This is suitable for controlling.

In order to control the axial ratio and the inclination of the major axis of the polarization ellipse of the electromagnetic waves radiated from the horn antenna, the methods shown in FIGS. 1 and 2, for example, have conventionally been used. In the example shown in FIG. 1, two types of phase plates l and 2 with different phase amounts are inserted into the cylindrical waveguide 3 in different directions, and these phase plates/
By rotating the and - directions, the cylindrical waveguide 3
By controlling the polarization ellipse of the electromagnetic waves propagating inside, a circularly polarized wave output j is obtained. Alternatively, in the example of FIG. 2, a first linearly polarized wave 9 with a constant amplitude and a constant phase and a second straight line with a variable power and a variable phase are transmitted through the rectangular waveguides 7 and r that are orthogonal to the cylindrical waveguide B. Deriving polarization input/θ. One end of the cylindrical waveguide B is closed with a perfect reflector //.

A phase plate 12 is arranged in the waveguide r. In this way,
In this example, an output 13 whose polarization ellipse is controlled by one orthogonal linear polarization input 9 and /θ is obtained.

Here, the power and phase of one linearly polarized input /θ are changed by a variable attenuator or a variable phase shifter that changes the phase by moving the phase plate 12 as shown, and the output 13 is changed.
control the polarization ellipse of As can be easily determined from FIG. 1 or 2, these methods have the drawback of requiring a very large-scale control mechanism such as a mechanism for rotating the phase plate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a small and lightweight polarization ellipse control device that eliminates the above-mentioned drawbacks, facilitates adjustment, and does not require a large-scale control mechanism.

In order to achieve this object, the polarization ellipse control device of the present invention provides a reflection device that reflects a part of the circularly polarized electromagnetic wave at the output end of the circularly polarized wave generator that obtains the circularly polarized wave from the excitation linearly polarized electromagnetic wave. a re-reflecting member is disposed in a direction perpendicular to the excitation linearly polarized wave at a position spaced apart from the reflecting member by a predetermined distance toward the input side, and the re-reflecting member allows the excitation linearly polarized wave to be reflected by the reflecting member. In a preferred embodiment of the present invention, a reflection ring is provided on the output side of the circularly polarized wave generator, and a plurality of reflection rings are provided on the input side of the circularly polarized wave generator. (For example, three) polarization ellipse adjustment screws are installed in a direction perpendicular to the direction of the input linearly polarized electric field, and by changing the insertion length of these adjustment screws, the long axis of the polarization ellipse can be adjusted. By changing the inclination and further changing the size of the reflective ring, the size of the axial ratio of the polarization ellipse is changed, thereby controlling the polarization ellipse.

The present invention will be described in detail below with reference to the drawings.

FIG. 3 shows the basic configuration of the present invention, in which a cylindrical waveguide with a circular cross section is used as a circularly polarized wave generator of a circularly polarized horn antenna. In this example, a rectangular-to-circular conversion waveguide 2/ to which an input linearly polarized wave is supplied, a circularly polarized wave generator n, and a horn B are coupled in cascade, but these have the conventional configuration as a circularly polarized horn antenna. In the present invention, in order to make the polarization ellipse variable, a reflection ring 2 is disposed at the output end 22B of the circularly polarized wave generator n, and a cylindrical waveguide is installed at the input side of the circularly polarized wave generator n. This cylindrical waveguide B is provided with a rod-shaped member, such as a screw 2tk, as a re-reflection member for polarization ellipse control.
2tB and 26C are installed. These screws 24A
, 2tB, and 26C have a structure that can be inserted into the cylindrical waveguide 22A in a direction perpendicular to the direction of the electric field AA' of the input linearly polarized wave. Although three screws, 2JA to 26G, are shown in the example of FIG. 3, more adjustment screws may be provided in order to improve the (j) adjustment accuracy of the polarization ellipse.

The operation of the reflection ring 21 thus provided on the output side of the circularly polarized wave generator n will be explained with reference to FIG. A-A
'In the circularly polarized wave generator n excited by the linearly polarized wave in the force direction, a circularly polarized wave is generated from its output end, and the reflection ring 24I
In the slow case, full power is supplied to horn n. However, when the reflective ring 2 is provided as in the present invention, a part of the circularly polarized wave generated by the circularly polarized wave generator n is reflected by the reflective ring 21 and supplied to the circularly polarized wave generator n again. This reflected wave becomes a linearly polarized wave at the input end 22A of the circularly polarized wave generator, and the direction of the electric field is BB' which is orthogonal to the electric field direction AA' of the excitation linearly polarized wave. now,
If the electric field strength of the excitation linearly polarized wave at the input end 22h of the circularly polarized wave generator is E□, the electric field strength ER of the B-B' force direction reflected wave 1 is equal to the reflection coefficient of the reflection ring 2tI. When the size is F, it is expressed as ER=r −E□ (1)(6). Further, the electric field strength ET of the transmitted wave j supplied to the horn B is expressed as ET=(/-4)E□ (2).

Therefore, by changing the reflection coefficient F as described below, the axial ratio of the polarization ellipse can be changed independently of other factors.

FIG. 5 is an explanatory diagram of the operation of the polarization ellipse control screws 24A, , 24B and 26G. The electric field ER of the linearly polarized wave l reflected by the reflection ring 2 is guided to the cylindrical waveguide 2S, where And, polarization ellipse adjustment screws, 2A, 26B, and
26C and supplied again to the circularly polarized wave generator n. The phase of this reflected wave is θ when using a screw, 24A.
Then, when screw 2tB is used, when screw 2B is used, the following is obtained. However, m and l are screws and 24A, respectively.
, j4B and the distance between screw 2tB and 26C, and λ is the wavelength within the cylindrical waveguide B. The important thing here is that each screw, 2≦A-! By changing the position or depth of 40 as shown in the figure, the phase of the reflected wave ER can be adjusted.
Any desired phase can be created by combining G's. Furthermore, since these screws 24A-2 are arranged in a direction perpendicular to the electric field E□ of the excitation linearly polarized wave, the electric field E is not affected in any way even if the screw 24A N260 is inserted.

Here, it will be explained with reference to FIG. 7 that the inclination and axial ratio of the polarization ellipse of the circularly polarized wave emitted from the horn n are determined by the amplitude and phase of the reflected wave ER. In the present invention, screw 26A,
By changing the position of -2tC, the phase difference α between ET and ER can be varied, and thus the slope β of the polarization ellipse can be controlled, as described above with respect to FIG. Furthermore, by changing the reflection coefficient F of the reflection ring 2, the axial ratio Ax of the polarization ellipse can be controlled. kojfETox(/-r)F,
1. Since ER=FE1, the axial ratio Ax of the polarization ellipse is
Ax=-(6) i-2r. Further, the slope β of the polarization ellipse is given by β=−(7).

Next, the operation of each part of the polarization ellipse control device of the present invention described above is as follows.
Taking the case of a polarized elliptical variable electromagnetic horn antenna as an example,
This will be explained in detail with reference to FIG.

A linearly polarized wave (Fig. r shows an example of vertically polarized wave) excited from a standard rectangular waveguide (not shown) passes through a rectangular-circular conversion waveguide J, thereby converting it into ■. A circular polarization generator n is excited with linear polarization in the direction of the electric field. What is important here is that the screw 24A-2tO inserted into the circular waveguide B is arranged in a direction perpendicular to the electric field direction of the incident wave (2), and does not affect the incident wave (2). In circular waveguide B,
A circularly polarized (q) wave generator excited by the incident wave (2) due to the electric field in the direction of the incident wave (2) produces, for example, a clockwise circularly polarized wave at its output end, as shown by (2). Note that ■ indicates a cross section of the circularly polarized wave generator n.

This circularly polarized wave ■ is divided into a wave that is reflected by the reflection ring 24' and a wave that passes through the reflection ring 24', and the wave that has passed through the reflection ring 2'l is [
F], it is a clockwise circularly polarized wave and is radiated from the horn 3. The wave reflected by the reflection ring 2 becomes a counterclockwise circularly polarized wave according to the law of reflection regarding circularly polarized waves, and passes through the circularly polarized wave generator n in the opposite direction to the incident wave. Therefore, the reflected wave ■ after passing through the circularly polarized wave generator n in the opposite direction is the incident wave ◎
It is a linearly polarized wave that is orthogonal to the .

Therefore, the reflected wave ■ entering the circular waveguide B is the reflected wave @
By inserting the screws 26A to 2ta placed in the direction of , into the circular waveguide B to a certain depth, the wave is completely reflected and becomes a linearly polarized wave like the reflected wave . and excite it. In this case, the reflected wave ■ by the screw is in the same direction as the reflected wave ■ by the reflection ring, but this reflected wave ■ is determined by the position of the screw, 24A-2AC (/θ) determined by each phase and the insertion length of the screw. It is a composite of reflected waves of a number corresponding to the number of screws having the same polarization direction and having different amplitudes. The phase of the combined reflected waves can be made arbitrary and desired by appropriately selecting the insertion depth, number, etc.

At the output end of the circularly polarized wave generator n, a counterclockwise circularly polarized wave as shown in (2) is obtained by this reflected wave (2). Note that when comparing the circularly polarized wave (2) with the circularly polarized wave (2), the direction of rotation, the initial position (phase) at which the rotation starts, and the amplitude (not shown in the figure) are different. This circularly polarized wave (■) passes through the reflection ring 2g, becomes a counterclockwise circularly polarized wave as shown by (■), and is radiated from the horn n. Note that the wave reflected by the reflection ring knob becomes very small from the second time onwards, so it can be ignored. Note that the radiated circularly polarized waves (2) and (2) differ in the direction of rotation, the initial position (phase) at which the rotation starts, and the amplitude. Therefore, the electromagnetic wave emitted from the horn sword becomes an elliptical polarized wave that is a combination of the circularly polarized waves ■ and ■, and the inclination and axial ratio of the polarized wave ellipse are (determined by A~240) and amplitude (determined by reflection ring 2).The amount of the wave reflected by reflection ring 2 is determined by the thickness t of ring 2. .

FIG. 9 shows the aforementioned reflection ring 241! For example, instead of q
Arrange the screws 3/, 32, 33 and 3 at equal intervals on the outer peripheral surface of the output end 2.2B of the circularly polarized wave generator n,
The insertion amount of these screws 3/~3g is determined by the drive device 35.
It is also possible to automatically control the amount of reflection by controlling by 3g. In this example, the amount of reflection of the reflected wave ER can also be automatically controlled by inputting the drive signals of the drive devices 35 to 3g into an automatic control loop.

Although the present invention has been described above with respect to an example using a circularly polarized wave generator using a circular waveguide, the present invention is not limited to this, and may also be applied to a circularly polarized wave generator using a square waveguide or the like. It is clear that the same structure can be used in the case of use.

As is clear from the above, according to the present invention, a reflecting member that reflects a part of the circularly polarized electromagnetic wave is disposed at the output end of the circularly polarized wave generator that obtains circularly polarized wave from the excitation linearly polarized electromagnetic wave. , a re-reflection member is disposed in a direction orthogonal to the excitation linearly polarized wave at a position separated from the reflection member by a predetermined distance toward the input side, and the re-reflection member redirects the reflected wave reflected by the reflection member. With a simple configuration that only allows re-reflection to the output side, a small and lightweight polarization ellipse control device that is easy to adjust can be realized without requiring a costly control mechanism.

Therefore, by using the horn incorporating the polarization ellipse control device of the present invention as the primary power feeder of the parabolic reflector,
A small, lightweight power feeder that can adjust the polarization ellipse can be realized. Furthermore, even when a horn incorporating the polarization ellipse control device of the present invention is used solely as a horn antenna, the polarization ellipse can be adjusted extremely easily. In addition, the polarization ellipse radiated from the horn antenna can be controlled by driving the reflection ring and polarization ellipse control screw, which are the components of the present invention, with a motor or the like, and inputting the driving power into an automatic control loop. Automatic control is also possible.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of two examples of the conventional polarization ellipse control method (/3), Figure 3 is a block diagram showing the basic configuration of the present invention, and Figure 7 is a diagram of the reflection ring. FIG. 9 is an explanatory diagram of the inclination and axial ratio of the polarization ellipse in which the operation is explained. FIG. g is an explanatory diagram of the operation of the apparatus of the present invention. FIG. /, 2... Phase plate, 3... Cylindrical waveguide, Da... Input linearly polarized wave, ! ... Output circular polarization, 6.
...Cylindrical waveguide, 7. t... rectangular waveguide?
, /θ...Linear polarization input, //...Perfect reflector, 1
2... Phase plate s/3... Output, 21.
...Rectangular-circular conversion waveguide, n...Cylindrical waveguide s j-2A...Input end, 22B...Output end, n...Pone, 2
'l...Reflection ring, Δ...Cylindrical waveguide, 2
4A, j! ;B, MuC...Polarization ellipse control screw,
1... Reflected wave, I... Transmitted wave, 3/
, 32 , 33 , 3g... reflection amount adjustment screw, 35
．． 3≦, n, 3g...screw drive device. (/41)

Claims (1)

[Claims] 1) A reflecting member that reflects a part of the circularly polarized electromagnetic wave is disposed at the output end of a circularly polarized wave generator that obtains circularly polarized wave from the excitation linearly polarized electromagnetic wave, and A re-reflection member is arranged in a direction perpendicular to the excitation linearly polarized wave at a position separated from the input side by a predetermined distance, and the re-reflection member re-reflects the reflected wave reflected by the reflection member to the output side again. A polarization ellipse control device characterized in that: 2) The polarization ellipse control device according to claim 1, wherein the reflecting member is constituted by a reflecting ring. 3) According to claim 1, the reflecting member is constituted by a plurality of screws arranged at approximately equal intervals on the same cross section as the output end tube wall of the circularly polarized wave generator. polarization ellipse controller. 4] The first aspect of the present invention is characterized in that the re-reflection member is constituted by a rod-shaped member, and the rod-shaped member can be inserted into a pipe of a waveguide coupled to the input end of the circularly polarized wave generator. The polarization ellipse control device according to any one of Items 1 to 3. 5) The polarization ellipse control device according to claim 4, wherein the rod-shaped member is at least one screw, and the screw is arranged in the axial direction of the circular waveguide.