A coaxial mode converter and a microwave radiation control method using the converter

Abstract

The present invention discloses a coaxial mode converter and a microwave radiation control method using the converter, mainly solving the problems that the input waveguide and the output waveguide of the existing converter are not on the same axis and the polarization direction of microwave radiation is difficult to control. The converter includes an input circular waveguide, a first inclined circular waveguide connected to the input circular waveguide and arranged obliquely, a circular straight phase-matching circular waveguide connected to the other end of the first inclined circular waveguide and parallel to the input circular waveguide, a second inclined circular waveguide symmetrically arranged about the center of the circular straight phase-matching circular waveguide, and an output circular waveguide connected to the other end of the second inclined circular waveguide; wherein, the centers of the input circular waveguide and the output circular waveguide are on the same axis. The present invention realizes the complete conversion from the TM01 mode of the circular waveguide to the TE11 mode of the circular waveguide, and outputs the microwave of the TE11 mode of the circular waveguide from the output end, while ensuring that the input waveguide and the output waveguide are on the same axis.

Description

Technical Field

[0001] The present invention relates to a microwave output structure of a vacuum microwave device, and more specifically, to a coaxial mode converter and a microwave radiation control method using the converter. Background Art

[0002] High-power microwave (HPM) is a new type of electromagnetic interference means, mainly used to interfere with and attack various targets such as electronic reconnaissance, communication, and synthetic aperture radar. It can degrade or damage microwave sensors, causing them to lose ground monitoring, and the reconnaissance and imaging to lose their corresponding reconnaissance and combat effectiveness. Since coaxial output has a wide-spectrum output characteristic and the working mode of most HPM devices (such as MILO, BWO, RKA) is the TM01 mode, the spatial radiation of this mode is a hollow beam, which is not conducive to the microwave acting on the target in practical applications. Usually, a special mode conversion structure is required to make the spatial radiation of the output microwave a solid beam. The existing mode converters are usually serpentine (or S-shaped) mode transformers. Since the input waveguide and the output waveguide are not on the same axis, it increases the difficulty of target alignment in practical applications. Moreover, although the polarization direction of the output microwave is parallel to the plane where the mode converter is located, the rotation of the mode converter will cause the offset movement of the output waveguide and the corresponding radiation horn, restricting the control of the polarization direction of the microwave radiation. Summary of the Invention

[0003] The purpose of the present invention is to provide a coaxial mode converter and a microwave radiation control method using the converter, mainly to solve the problems that the input waveguide and the output waveguide of the existing converter are not on the same axis and the polarization direction of the microwave radiation is difficult to control.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A coaxial mode converter includes an input circular waveguide, a first inclined circular waveguide connected to the input circular waveguide and inclined, a circular straight phase-matching circular waveguide connected to the other end of the first inclined circular waveguide and parallel to the input circular waveguide, a second inclined circular waveguide symmetrically arranged about the center of the circular straight phase-matching circular waveguide, and an output circular waveguide connected to the other end of the second inclined circular waveguide; wherein, the centers of the input circular waveguide and the output circular waveguide are on the same axis.

[0006] Further, in the present invention, the diameters of the input circular waveguide, the first inclined circular waveguide, the circular straight phase-matching circular waveguide, the second inclined circular waveguide, and the output circular waveguide are all 1.1 times the wavelength of the input microwave.

[0007] Further, in the present invention, the acute angles formed by the first inclined circular waveguide and the second inclined circular waveguide with the horizontal axis where the input circular waveguide and the output circular waveguide are located are 20°.

[0008] Further, in the present invention, the lengths of the first inclined circular waveguide and the second inclined circular waveguide are 3.0 times the wavelength of the input microwave.

[0009] Further, in the present invention, the length of the circular straight phase-matching circular waveguide is 1.6 times the wavelength of the input microwave.

[0010] Based on the above coaxial mode converter, the present invention also provides a method for controlling the polarization direction of microwave radiation, including the following steps:

[0011] (S1) Install a selection joint for realizing dynamic vacuum on the input circular waveguide and the output circular waveguide;

[0012] (S2) Fix a high-power microwave generator that generates TM01-mode microwaves with angular symmetry at one end of the input circular waveguide, and fix a radiation horn at the output end of the output circular waveguide;

[0013] (S3) Rotate the coaxial mode converter along the z-axis, then the polarization direction of the radiated microwave also changes accordingly as the coaxial mode converter rotates along the z-axis, thereby realizing the control of the polarization direction of microwave radiation.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) In the present invention, the microwave in the TM01 mode of the circular waveguide is input from the input end of the circular waveguide and enters the coaxial mode converter, so that the TM01-mode microwave is gradually converted into the TE11-mode microwave in the first inclined circular waveguide. During this mode conversion process, a circular straight phase-matching waveguide parallel to the input circular waveguide is installed at an appropriate position to change the phase-matching relationship during the mode conversion process to adapt to the continuation of the mode conversion process in the second inclined circular waveguide until the mode conversion is completed at the required position, realizing the complete conversion of the circular waveguide TM01 to the circular waveguide TE11 mode, and outputting the microwave in the circular waveguide TE11 mode from the output end, while ensuring that the input waveguide and the output waveguide are on the same axis.

[0016] (2) When the present invention is used, a selection joint for realizing dynamic vacuum is installed at the input and output waveguides. Although the high-power microwave generator and the radiation horn are fixed, the coaxial mode converter can still rotate along the z-axis mechanically. The microwave generated by the high-power microwave generator is in the TM01 mode and is angularly symmetric. Then, as the coaxial mode converter rotates along the z-axis, the polarization direction of the radiated microwave also changes accordingly as the coaxial mode converter rotates along the z-axis, thereby realizing the control of the polarization direction of microwave radiation. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the coaxial mode converter in the present invention.

[0018] Figure 2 It is a schematic diagram of the usage state structure of the coaxial mode converter in the present invention.

[0019] Figure 3 It is a distribution diagram of the microwave electric field (Ey) inside the coaxial mode converter in the present invention.

[0020] Figure 4 It is the radiation pattern inside the coaxial mode converter in the present invention.

[0021] Among them, the names corresponding to the reference numerals are:

[0022] 1 - input circular waveguide, 2 - first inclined circular waveguide, 3 - circular straight phase - matching circular waveguide, 4 - second inclined circular waveguide, 5 - output circular waveguide, 6 - selection joint, 7 - high - power microwave generator, 8 - radiation horn. Specific embodiments

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. The implementation manners of the present invention include but are not limited to the following embodiments.

[0024] Embodiment

[0025] As Figures 1 to 4 shown, a coaxial mode converter disclosed by the present invention includes an input circular waveguide 1, a first inclined circular waveguide 2 connected to and inclined with respect to the input circular waveguide 1, a circular straight phase - matching circular waveguide 3 connected to the other end of the first inclined circular waveguide 2 and parallel to the input circular waveguide 1, a second inclined circular waveguide 4 symmetrically arranged about the center of the circular straight phase - matching circular waveguide 3, and an output circular waveguide 5 connected to the other end of the second inclined circular waveguide 4; wherein, the centers of the input circular waveguide 1 and the output circular waveguide 5 are on the same axis.

[0026] Among them, the diameters of the input circular waveguide 1, the first inclined circular waveguide 2, the circular straight phase - matching circular waveguide 3, the second inclined circular waveguide 4, and the output circular waveguide 5 are all 1.1 ± 0.1 times the input microwave wavelength. The acute angles formed by the first inclined circular waveguide 2 and the second inclined circular waveguide 4 with the horizontal axis where the input circular waveguide 1 and the output circular waveguide 5 are located are 20 ± 0.1°. The lengths of the first inclined circular waveguide 2 and the second inclined circular waveguide 4 are 3.0 ± 0.1 times the input microwave wavelength. The length of the circular straight phase - matching circular waveguide 3 is 1.60 ± 0.1 times the input microwave wavelength.

[0027] In use, microwave in the TM01 mode of the circular waveguide is input from the input end of the circular waveguide and enters the coaxial mode converter. The microwave in the TM01 mode is gradually converted into microwave in the TE11 mode in the first inclined circular waveguide. During this mode conversion process, the phase-matching circular waveguide changes the phase-matching relationship in the mode conversion process to adapt to the continuation of the mode conversion process in the second inclined circular waveguide until the mode conversion is completed at the required position, realizing the complete conversion from the TM01 mode of the circular waveguide to the TE11 mode of the circular waveguide. The microwave in the TE11 mode of the circular waveguide is output from the output end. At the same time, it is also necessary to ensure that the input waveguide and the output waveguide are on the same axis.

[0028] At the same time, a selection joint 6 for realizing dynamic vacuum is installed at the input and output circular waveguides. Although the high-power microwave generator 7 and the radiation horn 8 are fixed, the coaxial mode converter can still rotate along the z-axis mechanically. The microwave generated by the high-power microwave generator is in the TM01 mode and is azimuthally symmetric. Then, as the coaxial mode converter rotates along the z-axis, the polarization direction of the radiated microwave also changes accordingly as the coaxial mode converter rotates along the z-axis. Thus, the control of the polarization direction of microwave radiation can be realized. Therefore, compared with the prior art, the present invention has outstanding substantial features and remarkable progress.

[0029] The above embodiments are only one of the preferred embodiments of the present invention and should not be used to limit the protection scope of the present invention. Any modification or polishing made without substantial meaning in the main design concept and spirit of the present invention, as long as the technical problems solved are still consistent with those of the present invention, should be included in the protection scope of the present invention.

Claims

1. A coaxial mode converter, characterized in that, It includes an input circular waveguide (1), a first inclined circular waveguide (2) connected to the input circular waveguide (1) and arranged obliquely, a circular straight phase-matching circular waveguide (3) connected to the other end of the first inclined circular waveguide (2) and parallel to the input circular waveguide (1), a second inclined circular waveguide (4) arranged symmetrically about the center of the circular straight phase-matching circular waveguide (3), and an output circular waveguide (5) connected to the other end of the second inclined circular waveguide (4); wherein, the centers of the input circular waveguide (1) and the output circular waveguide (5) are on the same axis. The diameters of the input circular waveguide (1), the first inclined circular waveguide (2), the circular straight phase-matching circular waveguide (3), the second inclined circular waveguide (4), and the output circular waveguide (5) are all 1.1 times the input microwave wavelength. Among them, the method for realizing the polarization direction control of microwave radiation by using this coaxial mode converter is as follows: (S1) Install selection joints for realizing dynamic vacuum on the input circular waveguide and the output circular waveguide. (S2) Fix a high-power microwave generator that generates TM01-mode microwaves with angular symmetry at one end of the input circular waveguide, and fix a radiation horn at the output end of the output circular waveguide. (S3) Rotate the coaxial mode converter along the z-axis, and the polarization direction of the radiated microwave will also change correspondingly as the coaxial mode converter rotates along the z-axis, thereby realizing the control of the polarization direction of microwave radiation.

2. The coaxial mode converter according to claim 1, wherein, The acute angles formed by the first inclined circular waveguide (2) and the second inclined circular waveguide (4) with the horizontal axis where the input circular waveguide (1) and the output circular waveguide (5) are located are 20°.

3. A coaxial mode converter according to claim 1, characterized in that, The lengths of the first inclined circular waveguide (2) and the second inclined circular waveguide (4) are 3.0 times the input microwave wavelength.

4. A coaxial mode converter according to claim 1, characterized in that, The length of the circular straight phase-matching circular waveguide is 1.6 times the input microwave wavelength.

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