Ka-band circular waveguide TE21 mode circular polarizer
By designing a Ka-band circular waveguide TE21 mode circular polarizer and adjusting the perturbation amount and waveguide radius using a micro-perturbation deformation structure, a highly efficient linear polarization signal to circular polarization signal conversion was achieved. This solved the problems of polarization efficiency and bandwidth expansion in helical corrugated waveguides and reduced the risk of high-frequency RF breakdown.
Patent Information
- Application Number
- CN202511655964.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-03-03
AI Technical Summary
Existing technologies struggle to efficiently convert high-order linearly polarized signals into circularly polarized signals, limiting the efficiency and performance of helical waveguides.
Design a Ka-band circular waveguide TE21 mode circular polarizer, comprising an input circular waveguide, an input gradient transition waveguide, a perturbation deformation phase shift waveguide, and an output gradient transition waveguide. By adjusting the perturbation amount and waveguide radius, the conversion from linearly polarized signals to circularly polarized signals can be achieved.
It improves circular polarization efficiency, expands bandwidth, reduces the risk of high-frequency RF breakdown, and is simple to manufacture and has a stable structure.
Smart Images
Figure CN121601996A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-power microwave device technology, and in particular to a Ka-band circular waveguide TE21 mode circular polarizer. Background Technology
[0002] High-power microwaves are widely used in radar, electronic warfare, and other fields. The gyrotron traveling-wave tube (TWT), a key research area in high-power microwaves, possesses advantages such as high power, high efficiency, and wide bandwidth, making it a high-performance high-power electromagnetic wave radiation source. The TWT utilizes the beam-wave interaction between the input electromagnetic wave and the electron beam emitted by the electron gun. This interaction gradually forms an angular cluster in the transverse direction, with the cluster center falling into a deceleration field. Ultimately, the electrons convert their own energy into output electromagnetic wave energy, thus amplifying the electromagnetic wave.
[0003] Helical corrugated waveguide gyro traveling-wave tubes (TWTs) can solve the size coherence effect in high-frequency bands compared to traditional vacuum microwave tubes and ordinary gyro traveling-wave tubes. Due to the unique dispersion curve of the helical corrugated waveguide, it can suppress higher-order mode competition and reduce the sensitivity to electron velocity dispersion to some extent. Therefore, research on helical corrugated waveguide TWTs has become one of the hot topics in international high-power device research. Because of the irregularity of the helical corrugated waveguide, the polarization mode transmitted within it is generally circularly polarized. Therefore, a waveguide circular polarizer needs to be added at its input to convert the higher-order linear polarization signal into the corresponding circularly polarized signal to improve the efficiency and performance of the helical corrugated waveguide. Summary of the Invention
[0004] The purpose of this invention is to provide a Ka-band circular waveguide TE21 mode circular polarizer, which aims to output the circular waveguide TE21 mode more efficiently, expand the bandwidth of the circular polarizer, and increase the polarization efficiency.
[0005] To achieve the above objectives, the present invention provides a Ka-band circular waveguide TE21 mode circular polarizer, comprising an input circular waveguide, an input gradient transition waveguide, a perturbation-shaped phase shift waveguide, an output gradient transition waveguide, and an output circular waveguide; the perturbation-shaped phase shift waveguide is connected to the input gradient transition waveguide and the output gradient transition waveguide respectively, and is located between the input gradient transition waveguide and the output gradient transition waveguide; the input circular waveguide is connected to the input gradient transition waveguide and is located on the side of the input gradient transition waveguide away from the perturbation-shaped phase shift waveguide; the output circular waveguide is connected to the output gradient transition waveguide and is located on the side of the output gradient transition waveguide away from the perturbation-shaped phase shift waveguide.
[0006] The lengths of the input circular waveguide and the output circular waveguide are both 5 mm.
[0007] The lengths of the input gradient transition waveguide and the output gradient transition waveguide are both 7.34 mm.
[0008] The length of the perturbation-shaped phase-shifting waveguide is 5.32 mm.
[0009] The perturbation amount of the micro-perturbation phase-shifting waveguide in the circular polarizer is 0.78 mm, and the radii of the input circular waveguide and the output circular waveguide are 6.88 mm.
[0010] This invention discloses a Ka-band circular waveguide TE21 mode circular polarizer. The two ports of the perturbation-shaped phase-shifting waveguide are connected to one end of the input gradient transition waveguide and one end of the output gradient transition waveguide, forming the main body of the polarizer. The other end of the input gradient transition waveguide is connected to the input circular waveguide, and the other end of the output gradient transition waveguide is connected to the output circular waveguide. The function of this waveguide circular polarizer is to convert the TE21 mode high-frequency linearly polarized signal of the input circular waveguide into the TE21 mode of the output circular waveguide. Specifically, the high-frequency circularly polarized signal of the mode is propagated through the input circular waveguide to the perturbation deformation waveguide, and then output to the output circular waveguide through the output gradual transition waveguide. At this time, the operating mode is switched from linear polarization TE21 mode to circular polarization TE21 mode. Compared with the traditional circular waveguide TE21 mode circular polarizer, by introducing a perturbation deformation waveguide structure, the perturbation amount of the perturbation deformation and the radii of the input circular waveguide and the output circular waveguide are adjusted to obtain a better circular polarization effect. Attached Figure Description
[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 This is a schematic diagram of a Ka-band circular waveguide TE21 mode circular polarizer provided by the present invention.
[0013] Figure 2 This is a side view of a Ka-band circular waveguide TE21 mode circular polarizer provided by the present invention.
[0014] Figure 3 This is a top view of a Ka-band circular waveguide TE21 mode circular polarizer provided by the present invention.
[0015] Figure 4 This is a schematic diagram of the port reflection parameters of the Ka-band circular waveguide TE21 mode circular polarizer.
[0016] Figure 5 This is a schematic diagram of the port transmission parameters of the Ka-band circular waveguide TE21 mode circular polarizer.
[0017] Figure 6 This is a schematic diagram of the transmission parameters and phase of a Ka-band circular waveguide TE21 mode circular polarizer.
[0018] Figure 7 This is a graph showing the axial ratio of the Ka-band circular waveguide TE21 mode circular polarizer as a function of frequency.
[0019] In the diagram: 1-Input circular waveguide, 2-Input gradient transition waveguide, 3-Perturbation phase-shifting waveguide, 4-Output gradient transition waveguide, 5-Output circular waveguide. Detailed Implementation
[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0021] Please see Figure 7 This invention provides a Ka-band circular waveguide TE21 mode circular polarizer. The perturbation-shaped phase-shifting waveguide 3 is connected to the input gradient transition waveguide 2 and the output gradient transition waveguide 4, respectively, and is located between the input gradient transition waveguide 2 and the output gradient transition waveguide 4. The input circular waveguide 1 is connected to the input gradient transition waveguide 2 and is located on the side of the input gradient transition waveguide 2 away from the perturbation-shaped phase-shifting waveguide 3. The output circular waveguide 5 is connected to the output gradient transition waveguide 4 and is located on the side of the output gradient transition waveguide 4 away from the perturbation-shaped phase-shifting waveguide 3.
[0022] In this embodiment of the invention, the two ports of the perturbation-shaped phase-shifting waveguide 3 are connected to one end of the input gradient transition waveguide 2 and one end of the output gradient transition waveguide 4, forming the main body of the polarizer. The other end of the input gradient transition waveguide 2 is connected to the input circular waveguide 1, and the other end of the output gradient transition waveguide 4 is connected to the output circular waveguide 5. The function of this waveguide circular polarizer is to convert the TE21 mode high-frequency linearly polarized signal of the input circular waveguide 1 into the TE21 mode high-frequency circular polarization signal of the output circular waveguide 5. Specifically, the polarization signal is propagated through the input circular waveguide 1 to the perturbation deformation waveguide 2, and then output to the output circular waveguide 5 through the output perturbation deformation waveguide 4. At this time, the operating mode is switched from linear polarization TE21 mode to circular polarization TE21 mode. Compared with the traditional circular waveguide TE21 mode circular polarizer, by introducing a perturbation deformation waveguide structure, the perturbation amount of the perturbation deformation and the radii of the input circular waveguide 1 and the output circular waveguide 5 are adjusted to obtain a better circular polarization effect.
[0023] To better understand this technical solution, the following embodiments are provided for further explanation:
[0024] Example
[0025] Input operating mode: Circular waveguide TE21 mode;
[0026] Operating band / frequency / mode: Ka / 28.5GHz-33GHz / TE21;
[0027] Appendix Figure 1 Schematic diagram of the novel circular waveguide TE21 mode circular polarizer; attached. Figure 2 Side view of the novel circular waveguide TE21 mode circular polarizer; attached Figure 3 A novel circular waveguide TE21 mode circular polarizer. This embodiment is a circular waveguide TE21 mode circular polarizer operating in the Ka band.
[0028] The input circular waveguide 1 and the output circular waveguide 5 have radii r2=a=6.88mm and length L3=5mm, and are symmetrical about the center.
[0029] The input gradient transition waveguide 2 and the output gradient transition waveguide 4 have radii a = 6.88 mm and a maximum disturbance b = 0.78 mm. Therefore, the minimum radius r1 = ab = 6.10 mm and the maximum radius r3 = a + b = 7.66 mm. The contour equation of the phase-shifting port along the circumferential direction is... , The angle value is in the circumferential direction. A linear transition is used between the two ports, with a length of L1=7.34mm. The input and output are symmetrical along the center.
[0030] The perturbation-deformed phase-shifting waveguide 3: The profile equations at both ends of this segment are as follows , Let be the angle value along the circumference, where the radius of the input circular waveguide 1 and the output circular waveguide 5 is a = 6.88 mm, and the maximum disturbance of the input gradient transition waveguide 2 and the output gradient transition waveguide 4 is b = 0.78 mm. Therefore, the minimum radius r1 = ab = 6.10 mm, the maximum radius r3 = a + b = 7.34 mm, and the length L2 = 5.32 mm.
[0031] The working principle of this circular polarizer is as follows: Due to the presence of the perturbation deformable waveguide, the electric field of the TE21 mode within the circular waveguide is decomposed into two electric fields in different directions. Two linearly polarized waves will propagate along the maximum radius perturbation direction and the shortest radius perturbation direction of the perturbation deformable waveguide, respectively. During this propagation, a phase difference will be generated. By adjusting the propagation length L2 of the two linearly polarized waves in the perturbation deformable phase-shifting waveguide 3, the phase difference between the two components of the circular waveguide TE21 mode can be ensured to reach ±π / 2. Therefore, the two transformed linearly polarized TE21 modes can be superimposed into a single circularly polarized TE21 mode.
[0032] The advantage of choosing a perturbation deformation structure is that the inner wall of the waveguide cavity has a smooth transition and there is no phase shifter, making the fabrication relatively simple. Most importantly, it can solve the RF breakdown problem of input signals at high power and high frequency.
[0033] Figure 4 The S11 parameter represents the reflection coefficient of the two orthogonal TE21 modes at the input port (port 1) to the two orthogonal TE21 modes at port 1. The reflection of the two orthogonal TE21 modes of this circular polarizer is below -30dB in the frequency range of 28.5GHz-33GHz, at which time the reflection of the two orthogonal TE21 modes is small.
[0034] Figure 5 The port transmission parameters of the Ka-band circular waveguide TE21 mode circular polarizer are given. S21 represents the transmission coefficient of the two orthogonal TE21 modes at the input port to the two orthogonal TE21 modes at the output port (2 ports). As shown in the figure, in the range of 28.5GHz-33GHz, the transmission coefficient of the two orthogonal TE21 modes is around 0.7 with an error of 0.1. At this time, the transmission of the two orthogonal TE21 modes is good.
[0035] Figure 6The transmission parameters of the Ka-band circular waveguide TE21 mode circular polarizer are shown in the figure. As can be seen from the figure, the phase of the transmission parameters of the two orthogonal TE21 modes changes uniformly and linearly, and the phase difference basically meets 90° with an error of about 1°. At this time, the phase of the two orthogonal TE21 modes meets the requirements.
[0036] Figure 7 The graph shows the axial ratio as a function of frequency for a Ka-band circular waveguide TE21 mode circular polarizer. The axial ratio is the ratio of the major axis to the minor axis in elliptical polarization. In engineering, elliptical polarized waves with an axial ratio less than 1.2 are generally considered to be approximately circularly polarized waves. The formula for axial ratio AR is:
[0037] ,
[0038] This represents the phase difference of the S21 parameters between two orthogonal TE21 modes, expressed in dB. The phase difference between the two orthogonal TE21 modes is shown in the figure. After calculation, it can be seen that the operating bandwidth of the circular polarizer at frequencies with an axial ratio of less than 1.2 is 3.5 GHz in the range of 28.5 GHz to 33 GHz.
[0039] The above description is merely a preferred embodiment of the Ka-band circular waveguide TE21 mode circular polarizer of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments, and equivalent variations made in accordance with the claims of the present invention, still fall within the scope of the invention.
Claims
1. A Ka-band circular waveguide TE21 mode circular polarizer, characterized in that... ； It includes an input circular waveguide, an input gradient transition waveguide, a perturbation-deformation phase-shifting waveguide, an output gradient transition waveguide, and an output circular waveguide; The perturbation-shaped phase-shifting waveguide is connected to the input gradient transition waveguide and the output gradient transition waveguide, respectively, and is located between the input gradient transition waveguide and the output gradient transition waveguide. The input circular waveguide is connected to the input gradient transition waveguide and is located on the side of the input gradient transition waveguide away from the perturbation-shaped phase-shifting waveguide. The output circular waveguide is connected to the output gradient transition waveguide and is located on the side of the output gradient transition waveguide away from the perturbation-shaped phase-shifting waveguide.
2. The Ka-band circular waveguide TE21 mode circular polarizer as described in claim 1, characterized in that... ； The lengths of the input circular waveguide and the output circular waveguide are 5 mm.
3. The Ka-band circular waveguide TE21 mode circular polarizer as described in claim 1, characterized in that... ； The lengths of the input gradient transition waveguide and the output gradient transition waveguide are 7.34 mm.
4. The Ka-band circular waveguide TE21 mode circular polarizer as described in claim 1, characterized in that... ； The length of the perturbation-shaped phase-shifting waveguide is 5.32 mm.
5. The Ka-band circular waveguide TE21 mode circular polarizer as described in claim 1, Its characteristics are: The perturbation amount of the micro-perturbation phase-shifting waveguide in the circular polarizer is 0.78 mm, and the radii of the input circular waveguide and the output circular waveguide are 6.88 mm.