Multi-arm diaphragm-loaded variable polarizer

Abstract

The application discloses a multi-arm diaphragm loading type variable polarizer, and aims at solving the defects of low power capacity of existing dielectric plate variable polarizer and ferrite variable polarizer. The application is composed of a multi-arm mode converter and two diaphragm loading type circular polarizers. The circular waveguide section of the multi-arm mode converter is connected with the first diaphragm loading type circular polarizer, and the circular waveguide section of the second diaphragm loading type circular polarizer is connected with the second diaphragm loading type circular polarizer. The multi-arm mode converter is composed of a power division structure, a power combination structure and N E-plane bent waveguides. The two diaphragm loading type circular polarizers are completely same and are composed of circular waveguides and metal diaphragms. The metal diaphragms are symmetrically welded on the inner walls of the third circular waveguides and present solid ship shapes. The application has high mode conversion efficiency, and the transmission efficiency at the central frequency is more than 99%. The application has simple structure, and the variable polarization function is easy to realize, and the power capacity of GW level can be realized.

Description

Technical Field

[0001] This invention relates to the field of high-power microwave devices, and more specifically to a multi-arm diaphragm-loaded variable polarizer. Background Technology

[0002] High-power microwaves (HPM) generally refer to strong electromagnetic radiation with frequencies between 300 MHz and 300 GHz, peak power greater than 100 MW, or average power greater than 1 MW. The applications of high-power microwaves are diverse, primarily including: high-power pulse radar for precise target discrimination over a wide bandwidth; high-energy particle radio frequency accelerators for research in high-energy physics and nuclear physics; controlled thermonuclear plasma heating based on the electron cyclotron resonance mechanism; and high-power microwave weapons.

[0003] Microwave polarizers are common devices in microwave and millimeter-wave technologies. Their main function is to switch between linear, left-hand circular, and right-hand circular polarization. They have wide applications in radar, communication, and electronic warfare systems. The performance of a microwave polarizer in target polarization tracking significantly impacts the performance of these systems. Conventional power-capacity polarizers mainly include dielectric slab polarizers and ferrite polarizers. Dielectric slab polarizers utilize the separation characteristics of dielectric slabs to separate waves from different directions to achieve polarization. Due to the introduction of dielectric materials, their power capacity is relatively low, below the hundreds of megawatts, and does not meet the requirements of high-power microwave applications. Ferrite polarizers use ferrite materials and adjust polarization by changing the amplitude of the applied magnetic or electric field, thereby altering the propagation constant of the ferrite material. Ferrite polarizers typically have power capacities ranging from one or two hundred kilowatts (X-band) to megawatts (C-S band), classifying them as high-power capacity polarizers. In the field of high-power microwave research, due to the strong electromagnetic field characteristics of high-power microwave devices, existing microwave polarizers are limited by power capacity and cannot be truly applied in the field of high-power microwave.

[0004] Therefore, how to provide a new type of high-power microwave polarizer with a power capacity of up to GW has always been a hot research topic in this field. Summary of the Invention

[0005] The technical problem to be solved by this invention is:

[0006] To address the shortcomings of existing dielectric plate polarizers and ferrite polarizers in terms of low power capacity, a multi-arm diaphragm-loaded polarizer is provided to achieve switching between linear polarization, left-hand circular polarization, and right-hand circular polarization, with a power capacity reaching the GW level.

[0007] The technical solution of this invention is:

[0008] The present invention consists of a multi-arm mode converter and two diaphragm-loaded circular polarizers. The circular waveguide section of the multi-arm mode converter is docked with that of the first diaphragm-loaded circular polarizer, and the circular waveguide section of the second diaphragm-loaded circular polarizer is docked with that of the second diaphragm-loaded circular polarizer. The multi-arm mode converter is composed of a disc-shaped multi-way power divider structure, a disc-shaped multi-way power combiner structure, and N E-plane bent waveguides. The two diaphragm-loaded circular polarizers are exactly the same and are composed of a circular waveguide and metal diaphragms. The metal diaphragms are symmetrically welded to both sides of the inner wall of the third circular waveguide along the axis of the third circular waveguide, presenting a solid ship shape.

[0009] The present invention is prepared from a metallic material (preferably aluminum) and consists of a multi-arm TM01-TE11 circular polarization mode converter and two diaphragm-loaded circular polarizers. The circular waveguides of the multi-arm TM01-TE11 circular polarization mode converter and the two diaphragm-loaded circular polarizers are connected in sequence.

[0010] The multi-arm TM01-TE11 circular polarization mode converter is composed of a disc-shaped multi-way power divider structure, N 180-degree E-plane bent waveguides, and a disc-shaped multi-way power combiner structure. The disc-shaped multi-way power divider structure and the disc-shaped multi-way power combiner structure are connected by 180-degree E-plane waveguides.

[0011] The disc-shaped multi-way power divider structure consists of a first circular waveguide, a first inner conductor, and a first cylindrical cavity. One end of the first cylindrical cavity is open, and the first inner conductor is coaxially nested inside the first cylindrical cavity. The first circular waveguide is connected to the open end of the first cylindrical cavity. One end of the first circular waveguide is the input port of the microwave. The first inner conductor is composed of a frustum structure. The bottom of the frustum structure of the first inner conductor is connected to the closed end face of the first cylindrical cavity, and N rectangular holes are evenly opened on the side surface of the first cylindrical cavity, where N≥6 and N is an even number. The first circular waveguide and the first cylindrical cavity are chamfered to D1, the chamfer depth is H1, and the chamfer radius is r1 at the chamfer connection.

[0012] The diameter of the first circular waveguide is D0, the length is H0, and the thickness is d; the top diameter of the frustum of the first inner conductor is D2, the bottom diameter is D3, the height is H2, and the thickness is d; the diameter of the first cylindrical cavity is D7 (generally (1-2)×N×a / π), the length is b, the thickness is d, and N rectangular waveguides with a wide side length of a, a narrow side length of b, and a distance from the axis of D7 / 2 are evenly opened on the side surface of the first cylindrical cavity for connecting to the 180-degree E-plane bent waveguide, where N≥6 and N is an even number, λ0 / 2<a<3λ0 / 2, b<λ0 / 2, and λ0 is the free space wavelength of the input microwave. The disc-shaped multi-way power divider structure divides the TM01 mode input from the port of the first circular waveguide into N TE10 modes, and the N TE10 modes will be transmitted through the N rectangular holes with a wide side length of a and a narrow side length of b distributed radially.

[0013] The 180-degree E-plane bend waveguide is used to connect the disk-shaped power divider and the disk-shaped power combiner. It is angularly distributed, with a bend waveguide port size of a×b. The height of the 180-degree E-plane bend waveguide, HA, is 2 to 10 times the waveguide height b. The N E-plane bend waveguides have different radial lengths, R... n (n = 1, 2, ..., N), and R1≥b, where λ0 is the wavelength of the input microwave in free space. The E-plane bend angle is 180 degrees, the inner wall chamfer radius is r3, the outer wall C-shaped chamfer radius is H3, and the inner wall thickness is equal to d. The microwave input end of the 180-degree E-plane bend waveguide is uniformly connected to the rectangular waveguide of the first cylindrical cavity. The 180-degree E-plane bend rectangular waveguide structure will generate the TE from the power divider structure. 10 The transmission direction of the mode is reversed, and the TE of each 180-degree E-plane curved waveguide structure is adjusted by varying the length of each structure. 10 The output phase of the mode. The disk-type power combiner and disk-type power divider have basically the same shape.

[0014] The disk-shaped multiplexer structure consists of a second circular waveguide, a second inner conductor, and a second cylindrical cavity, with one end of the second cylindrical cavity open. The second inner conductor is coaxially nested within the second circular waveguide and the second cylindrical cavity. One end of the second circular waveguide serves as the microwave output port of the circularly polarized TE11 mode multi-arm mode converter. The second inner conductor comprises two frustum structures and one cylindrical structure. The bottom of the first frustum structure of the second inner conductor is connected to the closed end face of the second cylindrical cavity.

[0015] The second circular waveguide has a diameter of D0, a length of H8, and a thickness of d. The first frustum of the second inner conductor has a bottom diameter of D4, a top diameter of D5, a height of H4, and a thickness of d. The cylinder of the second inner conductor has a diameter of D5, a length of H6, and a thickness of d. The second frustum of the second inner conductor has a bottom diameter of D5, a top diameter of D6, and a height of H8. The second cylindrical cavity has a diameter of D7, a length of b, and a thickness of d. N rectangular waveguides with a wide side length of a, a narrow side length of b, and a distance from the axis of D7 / 2 are uniformly formed on the side of the second cylindrical cavity to connect to the microwave output end of the 180-degree E-plane curved waveguide. The disk-shaped power combining structure combines the power of N rectangular TE10 modes with different phases and outputs the combined microwave mode through the output port of the second circular waveguide. The second circular waveguide and the second cylindrical cavity have a C-shaped chamfer with a chamfer depth of H5; the first frustum of the second inner conductor and the second cylindrical cavity have a C-shaped chamfer with a chamfer depth of H4; the chamfer radius at the connection between the cylinder and the second frustum of the second inner conductor is r4; and the chamfer radius at the top of the frustum of the second inner conductor is r5.

[0016] The rectangular waveguides on the sides of the N first cylindrical cavities are mechanically connected to the input ports of the N 180-degree E-plane bent waveguides respectively, and the output ports of the N 180-degree E-plane bent waveguides are mechanically connected to the rectangular waveguides on the sides of the N second cylindrical cavities respectively.

[0017] The diaphragm-loaded circular polarizer is composed of a third circular waveguide and metal diaphragms. The third circular waveguide is made of a metal material, is a hollow cylinder, with an inner radius of R0, a length of L1, and a thickness of d; the metal diaphragms are symmetrically welded along the axis of the third circular waveguide to both sides of the inner wall of the third circular waveguide, and are respectively denoted as the first diaphragm and the second diaphragm. The shapes of the first diaphragm and the second diaphragm are exactly the same, and are in the shape of a solid boat. The central positions of the first diaphragm are equidistant from the input port and the output port. The first diaphragm consists of a first left diaphragm ramp, a first diaphragm middle section, and a first right diaphragm ramp. Among them, the shapes of the first left diaphragm ramp and the first right diaphragm ramp are exactly the same, and are in the shape of an obliquely cut cylinder (that is, the part of a solid cylinder that has only three faces after being divided by a plane intersecting the cylinder end face and the cylinder side). The axial length of the first left diaphragm ramp is L2. The first diaphragm middle section is in the shape of a horizontal cross-section of a cylinder (that is, the part of a solid cylinder that has inferior arcs at both ends after being divided by a plane intersecting both end faces and parallel to the axis), and its axial length is L3 and the thickness is h. The connection position between the first left diaphragm ramp and the first diaphragm middle section is chamfered with a chamfer radius of r. The connection position between the first right diaphragm ramp and the first diaphragm middle section is chamfered.

[0018] The output end of the multi-arm mode converter is mechanically connected to the input end of the first diaphragm-loaded circular polarizer, and the output end of the first diaphragm-loaded circular polarizer is connected to the input end of the second diaphragm-loaded circular polarizer through a rotary joint.

[0019] For the convenience of description, the conditions satisfied by the structural parameters of the above design are uniformly introduced here:

[0020] 1. The parameters a and b of the 180-degree E-plane bent waveguide satisfy the condition that only the TE 10 mode exists in the rectangular waveguide, that is, λ0 / 2 < a < 3λ0 / 2, b < λ0 / 2, where λ0 is the free space wavelength of the input microwave. After a and b are determined, according to the microwave transmission theory, the power capacity P0 of the rectangular waveguide transmitting the TE 10 mode is determined by P0 = f(a, b). Therefore, the power capacity P of the N rectangular waveguides is P = N×P0. Increasing N can increase the power capacity of the mode converter. According to the device structure, the diameters D0 of the first circular waveguide and the second circular waveguide must satisfy a certain relationship: through electromagnetic simulation software such as HFSS software, it is simulated that the radius r0 of the first circular waveguide and the radius r1 of the first inner conductor cylinder satisfy that the TM01 mode can pass through the coaxial waveguide formed, that is, D0 ≥ 4π / λ0 / 2.4048.

[0021] 2. H0>λ0 / 4, H8>λ0 / 4, H2>0, H4>0.

[0022] 3. After determining the cross-sectional dimensions a and b of the 180-degree E-plane curved waveguide, the diameter D0 of the first circular waveguide at the input end, the diameter D7 of the first cylindrical cavity (generally (1-2) × N × a / π), and the height HA of the 180-degree E-plane curved waveguide (generally 2-10 times the waveguide height b), the electromagnetic simulation software HFSS is used to set the transmission efficiency of microwave transmission to the output end of the multi-arm mode converter to be greater than 99% and the output phase TE to be greater than 99% under the conditions that H0>λ0 / 4, H8>λ0 / 4, H2>0, and H4>0. 11 With the modes out of phase by 90 degrees, parameters D1, H1, D2, D3, H2, and R can be obtained. n The precise values ​​of H3, D5, D6, H5, H6, and D4, with d typically taken as 3-5 mm.

[0023] 4. The changes in the axial length L3 and thickness h of the middle section of the first diaphragm in the circular polarizer can alter TE. 11 The mode cutoff wavelength was determined by calculating the vertical component cutoff wavelength λ of the first diaphragm under different conditions using the electromagnetic simulation software CST. c1 The cutoff wavelength λ of the parallel component of the first diaphragm c2 This makes L3(k1-k2)=π / 4, where k1 is the phase shift constant perpendicular to the middle section 222 of the first diaphragm, and k2 is the phase shift constant parallel to the middle section 222 of the first diaphragm. The approximate value of L3 is obtained from L3=π / 4 / (k1-k2).

[0024] The cutoff wavelength λ of the vertical component of the first diaphragm under different conditions was calculated using the electromagnetic simulation software CST. c1 The cutoff wavelength λ of the parallel component of the first diaphragm c2 This allows us to obtain the initial value of L3, which is L3 = π / 4 / (k1-k2). Then, we set the microwave input to the first circular waveguide of the diaphragm-loaded circular polarizer and the output to the second circular waveguide, with a transmission efficiency greater than 99%. Additionally, in the circular polarization output mode, TE... 11 The two polarization components of the mode have equal amplitudes and a phase difference of 90°. After optimization, the precise values ​​of the membrane parameters L2, L3, and h can be obtained.

[0025] The working process of this invention is as follows:

[0026] A disk-shaped power divider transmits TM01 mode microwaves radially, distributing power to N 180-degree E-plane bend waveguides, thus converting the microwaves from the circular waveguide TM01 mode to the rectangular waveguide TE10 mode. Next, due to the different radial lengths of the N 180-degree E-plane bend waveguides, the output phase of each TE10 mode is adjusted. Finally, a disk-shaped power combiner synthesizes the N TE10 mode microwaves to output a circularly polarized TE11 mode. In the first diaphragm-loaded circular polarizer, the first diaphragm and second module decompose the circularly polarized TE11 mode microwaves into two orthogonal TE11 modes. Adjusting the parameters of the first diaphragm and second module ensures that the phase difference between the two orthogonal TE11 modes is zero, resulting in a linearly polarized TE11 mode output. The second diaphragm-loaded circular polarizer converts linearly polarized TE11 mode microwaves into circularly polarized TE11 mode. By rotating the second diaphragm-loaded circular polarizer to the linear polarization direction at angles of -45°, 0°, and +45°, it can output microwaves with three different polarizations: left-hand circular polarization, linear polarization, and right-hand circular polarization, thus realizing variable polarization applications.

[0027] Compared with the prior art, the present invention can achieve the following technical effects:

[0028] This invention features a simple structure, high mode conversion efficiency (up to 99%), easy implementation of polarization conversion, large power capacity (up to GW level under vacuum conditions), and a 180-degree E-plane curved waveguide distributed angularly, with the TE10 mode propagating radially. It is relatively compact in the axial direction and can achieve switching between three different polarization modes: left-hand circular polarization, linear polarization, and right-hand circular polarization, adapting to the needs of high-power microwave experiments and applications in various situations. Attached Figure Description

[0029] Figure 1 This is an isometric view of the overall structure of the present invention.

[0030] Figure 2 This is a side view of the overall structure of the present invention.

[0031] Figure 3 This is an isometric view of the overall structure of the multi-arm mode converter 1 of the present invention.

[0032] Figure 4 yes Figure 3 Exploded isometric view.

[0033] Figure 5 yes Figure 3 Side view of the explosion.

[0034] Figure 6 yes Figure 5 A cross-sectional view along the CC' plane.

[0035] Figure 7This is a top view of the disk-shaped multi-path power divider structure 11.

[0036] Figure 8 This is a top view of the disc-shaped multi-channel power combination structure 13.

[0037] Figure 9 This is a schematic diagram of the structure of the first diaphragm-loaded circular polarizer 2 of the present invention.

[0038] Figure 10 yes Figure 9 A sectional view along the BB' plane.

[0039] Figure 11 This is a schematic cross-sectional view of the first diaphragm 22 and the second diaphragm 23.

[0040] Figure 12 This is a schematic diagram of the first left diaphragm 221 of the present invention being obliquely cut into a cylindrical shape.

[0041] Figure 13 This is a schematic diagram of the first diaphragm of the present invention with the middle section 222 in the shape of a horizontally cut cylinder.

[0042] Figure 14 This is a schematic diagram of the left-handed rotation of the present invention.

[0043] Figure 15 This is a schematic diagram of the right-handed rotation of the present invention. Detailed Implementation

[0044] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] Figure 1 This is an isometric view of the overall structure of the multi-arm diaphragm-loaded variable polarizer of the present invention. Figure 2 This is a side view of the overall structure of the present invention. (See image below.) Figure 1 and Figure 2 As shown, the multi-arm diaphragm-loaded variable polarizer consists of a multi-arm mode converter 1 and two diaphragm-loaded circular polarizers (let's call them the first diaphragm-loaded circular polarizer 2 and the second diaphragm-loaded circular polarizer 3). The multi-arm mode converter 1 is mechanically connected to the first diaphragm-loaded circular polarizer 2, and the first diaphragm-loaded circular polarizer 2 and the second diaphragm-loaded circular polarizer 3 are connected by a rotary joint. The first diaphragm-loaded circular polarizer 2 and the second diaphragm-loaded circular polarizer 3 can rotate coaxially.

[0046] Figure 3 This is an overall isometric view of the multi-arm mode converter 1 of the present invention. Figure 4 yes Figure 3 Exploded isometric view, Figure 5 yes Figure 3 Explosion side view, Figure 6 yes Figure 5 Cross-sectional view of the BB' section. As Figure 6 shown, the multi-arm mode converter 1 consists of a disc-shaped multi-way power divider structure 11, N 180-degree E-plane bent waveguides 12, and a disc-shaped multi-way power combiner structure 13. The disc-shaped multi-way power divider structure 11 and the disc-shaped multi-way power combiner structure 13 are connected by N 180-degree E-plane bent waveguides 12.

[0047] As Figure 5 shown, the disc-shaped multi-way power divider structure 11 consists of a first circular waveguide 111, a first inner conductor 113, and a first cylinder 112. One end of the first cylinder 112 is open, and the other end is closed. The first inner conductor 113 is coaxially nested inside the cylinder near the closed end. One end of the first circular waveguide 111 is coaxially connected to the open end of the first cylinder 112 through a chamfer. The other end of the first circular waveguide 111 is the input port of the microwave, and the chamfer radius between the first circular waveguide 111 and the first cylinder 112 is D1, and the chamfer depth is H1. The shape of the first inner conductor 113 is a frustum of a cone, and the bottom of the frustum of the cone of the first inner conductor 113 closely adheres to the inner surface of the closed end of the first cylinder 112.

[0048] As Figure 5 shown, the diameter of the first circular waveguide 111 is D0, the length is H0, and the side wall thickness of the first circular waveguide 111 is d; as Figure 6 shown, the top diameter of the frustum of the cone of the first inner conductor 113 is D2, the bottom diameter is D3, the height is H2, and the thickness is equal to d; the outer diameter of the first cylinder 112 is D7, the length is b, the side wall thickness is equal to d, and N rectangular waveguides (i.e., the first rectangular waveguide 1111,..., the nth rectangular waveguide 111n,..., the Nth rectangular waveguide 111N) are evenly extended on the side surface of the first cylinder 112 (as Figure 7 shown), N≥6 and N is a positive even number, 1≤n≤N. The length of the rectangular waveguide is a, the width is equal to b, and the distance from the center axis of the first cylinder 112 is D7 / 2. The N rectangular waveguides are respectively connected to N 180-degree E-plane bent waveguides 12, λ0 / 2 < a < 3λ0 / 2, b < λ0 / 2, where λ0 is the free space wavelength of the input microwave. The disc-shaped multi-way power divider structure 11 divides the TM01 mode microwave input from the port of the first circular waveguide 111 into N TE10 mode microwaves, and the N TE10 mode microwaves are respectively transmitted to the disc-shaped power combiner structure 13 through the N 180-degree E-plane bent waveguides 12 distributed radially.

[0049] The N 180-degree E-plane bent waveguides 12 are used to connect the disc-shaped multi-way power divider structure 11 and the disc-shaped multi-way power combiner structure 13, and are angularly distributed. The port size is a×b, that is, the length of the 180-degree E-plane bent waveguide 12 is equal to a, and the width is equal to b; the radial lengths of the N E-plane bent waveguides are different, which are R1,..., R n ,..., R N , and when n is greater than or equal to 2, R1≥b, where λ0 is the wavelength of the input microwave in free space. The E-plane bending angle of the 180-degree E-plane curved waveguide 12 is 180 degrees, the inner wall chamfer radius is r3, the outer wall C-shaped chamfer radius is H3, and the inner wall thickness is equal to d. The microwave input terminals of N 180-degree E-plane curved waveguides 12 are respectively connected to N rectangular waveguides of the first cylinder 112. The N 180-degree E-plane curved rectangular waveguides 12 will transmit the TE generated by the connected disk-shaped power divider structure 11 to the N rectangular waveguides. 10 The transmission direction of the mode is reversed, and the different radial lengths of the N 180-degree E-plane curved waveguides 12 correspond to the TE in the 180-degree E-plane curved waveguide 12. 10 The output phase of the mode.

[0050] like Figure 5 As shown, the disk-shaped multi-channel power combining structure 13 consists of a second circular waveguide 131, a second inner conductor 133, and a second cylinder 132. The second cylinder 132 is open at one end and closed at the other. The second inner conductor 133 is coaxially nested inside the second circular waveguide 131 and the second cylinder 132. One end of the second circular waveguide 131 is the microwave output port of this invention. The second inner conductor 133 consists of two frustums (let's call them the first frustum 1331 and the second frustum 1332) and a cylinder 1333. The bottom of the first frustum structure 1331 of the second inner conductor 133 is tightly attached to the inner surface of the closed end of the second cylinder 132.

[0051] like Figure 6 As shown, the second circular waveguide 131 has a diameter of D0, a length of H8, and a sidewall thickness of d; the first frustum 1331 of the second inner conductor 133 has a bottom diameter of D4, a top diameter of D5, a height of H4, and a sidewall thickness of d; the cylinder 1333 of the second inner conductor 133 has a diameter of D5, a length of H6, and a sidewall thickness of d; the second frustum 1332 of the second inner conductor 133 has a bottom diameter of D5, a top diameter of D6, and a height of H8; the second cylinder 132 has a diameter of D7, a length of b, and a sidewall thickness of d, and N second cylindrical rectangular waveguides (i.e., first second cylindrical rectangular waveguide 1311, ..., nth second cylindrical rectangular waveguide 131n, ..., Nth second cylindrical rectangular waveguide 131N) with a length of a and a width of b, and a distance of D7 / 2 from the central axis of the second cylinder 132, are evenly distributed on the side of the second cylinder 132. Figure 8As shown), it is used to connect to the microwave output terminals of N 180-degree E-plane curved waveguides 12. The disk-shaped power combining structure 13 combines N rectangular TE10 mode microwaves of different phases output from the N 180-degree E-plane curved waveguides 12, and outputs the combined microwaves through the output port of the second circular waveguide 131. The connection between the second circular waveguide 131 and the second cylinder 132 is C-shaped chamfered with a chamfer depth of H5; the first frustum 1331 of the second inner conductor 133 is also C-shaped chamfered with the second cylinder 132 with a chamfer depth equal to H4; the chamfer radius at the connection between the cylinder 1333 of the second inner conductor 133 and the second frustum 1332 is r4; the chamfer radius at the top of the frustum of the second inner conductor 133 is r5.

[0052] Figure 9 This is a three-dimensional view of the first diaphragm-loaded circular polarizer 2. Figure 10 yes Figure 9 BB' planar section view, Figure 11 for Figure 10 Cross-sectional views of the first diaphragm 22 and the second diaphragm 23; as shown Figure 9 As shown, the diaphragm-loaded circular polarizer 2 consists of a third circular waveguide 21, a first diaphragm 22, and a second diaphragm 23. The third circular waveguide 21 is made of a metallic material (preferably aluminum), with an inner radius of R0, a length of L1, and a sidewall thickness equal to d. The first diaphragm 22 and the second diaphragm 23 are symmetrically welded to the inner wall of the third circular waveguide 21 along its axis OO'. The center of the first diaphragm 22 is equidistant from both the input and output ports. The first diaphragm 22 and the second diaphragm 23 have identical shapes, resembling a solid boat. Figure 11 As shown, the first diaphragm 22 is composed of a first left diaphragm slope 221, a middle section 222 of the first diaphragm, and a first right diaphragm slope 223. The first left diaphragm slope 221 and the first right diaphragm slope 223 have identical shapes. The first left diaphragm slope 221 is obliquely shaped like a cylinder (i.e., a solid cylinder is divided by a plane intersecting the end face and the side face of the cylinder, leaving only three faces). Figure 12 The blue portion of the first diaphragm has an axial length of L2 for the slope 221 of the first left diaphragm. The middle section 222 of the first diaphragm is horizontally transversely slit in the shape of a cylinder (i.e., the part where the arc at both ends is a minor arc after the solid cylinder is divided by a plane that intersects the two end faces and is parallel to the axis). Figure 13 The blue portion of the first diaphragm has an axial length of L3 and a thickness of h (see blue portion). Figure 10The first right diaphragm ramp 223 is chamfered at the junction with the middle section 222 of the first diaphragm, with a chamfer radius of r. The second diaphragm 23 consists of the second left diaphragm ramp 231, the middle section 232 of the second diaphragm, and the second right diaphragm ramp 233, wherein the shapes of the second left diaphragm ramp 231 and the second right diaphragm ramp 233 are identical. The axial length of the second left diaphragm ramp 231 is equal to L2, the axial length of the middle section 232 of the second diaphragm is equal to L3, and the thickness of the middle section 232 of the second diaphragm is equal to h (see...). Figure 10 The second right diaphragm ramp 233 is chamfered at the connection point with the middle section 232 of the diaphragm, with a chamfer radius equal to r. The third circular waveguide 21 is the output waveguide of the diaphragm-loaded circular polarizer 2. The first diaphragm 22 and the second diaphragm 23 achieve circular polarization by changing the propagation constant of the electromagnetic wave in the direction perpendicular to the diaphragm. The third circular waveguide 21 is mechanically connected to the multi-arm mode converter 1.

[0053] The second diaphragm-loaded circular polarizer 3 is exactly the same as the first diaphragm-loaded circular polarizer 2, and the second diaphragm-loaded circular polarizer 3 and the first diaphragm-loaded circular polarizer 2 are connected by a rotary joint.

[0054] Figure 14 This is a schematic diagram of the left-handed mode of the present invention; Figure 15 This is a schematic diagram of the right-handed polarization mode of the present invention; when the angle between the second diaphragm-loaded circular polarizer 3 and the first diaphragm-loaded circular polarizer 2 is 45° (viewed from the input end, counterclockwise direction is positive) (e.g. Figure 14 The output is a left-hand circularly polarized microwave; when the angle between the second diaphragm-loaded circular polarizer 3 and the first diaphragm-loaded circular polarizer 2 is -45° (viewed from the input end, counterclockwise is positive) (e.g. Figure 15 The output is a right-hand circularly polarized microwave; when the angle between the second diaphragm-loaded circular polarizer 3 and the first diaphragm-loaded circular polarizer 2 is 0° (e.g. Figure 1 As shown in the figure, the output is a linearly polarized microwave.

[0055] The following provides specific design dimensions for an example of a multi-arm diaphragm-loaded variable polarizer used at 1.62 GHz (i.e., the input microwave source frequency is 1.62 GHz):

[0056] In the multi-arm mode converter 1, the first circular waveguide 111 has a diameter D0 = 210 mm, a length H0 = 150 mm, a sidewall thickness d = 5 mm, and a C-shaped chamfer depth H1 = 70 mm with the first cylinder 112, a diameter D1 = 145 mm, and a chamfer r1 = 10 mm at the connection; the first cylinder 112 has a diameter D7 = 400 mm, a height b = 82.5 mm, a sidewall thickness d = 5 mm, and a rectangular aperture with a length a = 165.1 mm and a width b = 82.5 mm; the first inner conductor 113 is circular... The top diameter of the platform is D2 = 66mm, the bottom diameter is D3 = 127mm, and the height is H2 = 45mm. The number of 180-degree E-plane bent waveguides (N) is 6. The radial lengths of the bent waveguides are R1 = 100mm, R2 = 118.62mm, R3 = 137.24mm, R4 = 155.86mm, R5 = 174.48mm, and R6 = 193.1mm. The axial length is HA = 245mm. The inner wall chamfer radius is r3 = 19.8mm, and the outer wall C-shaped chamfer radius is H3 = 6. 4.5mm, sidewall thickness d=5mm; the second circular waveguide 131 has a diameter D0=105mm, length H8=300mm, sidewall thickness d=5mm, and a C-shaped chamfer depth H5=62.8mm with the second cylinder 132; the second cylinder 132 has a diameter D7=400mm, height b=82.5mm, thickness d=5mm, rectangular hole length a=165.1mm, width b=82.5mm; the second inner conductor 133 has a bottom diameter D4=165mm of the first frustum 1331. m, top diameter D5 = 80mm, height H4 = 62.8mm; second inner conductor 133 cylinder 1333 diameter D5 = 80mm, height H6 = 100mm; second inner conductor 133 second frustum 1332 bottom diameter D5 = 80mm, top diameter D6 = 30mm, second inner conductor 133 sidewall thickness d = 5mm, chamfer radius r4 = 40mm at the junction of the second frustum 1332 and cylinder 1333, chamfer radius r5 = 5mm at the top of the second frustum 1332.

[0057] In the first diaphragm-loaded circular polarizer 2 and the second diaphragm-loaded circular polarizer 3, the third circular waveguide 21 is made of metal with an inner radius of R0 = 105 mm and a length of L1 = 680 mm; the axial length of the left diaphragm ramp 221 is L2 = 122.3 mm, the axial length of the middle section 222 of the first diaphragm is L3 = 192.4 mm, and the thickness is h = 34.9 mm. The chamfer radius r = 32.3 mm is at the connection point between the left diaphragm ramp 221 and the middle section 222 of the first diaphragm 22.

[0058] Adjusting the angle between diaphragm-loaded circular polarizer 3 and diaphragm-loaded circular polarizer 2 to 45° (viewed from the input end, counterclockwise direction is positive), simulation in electromagnetic simulation software CST (2022) shows that the output is a left-handed TE11 circular polarization mode. The axial ratio is 1.03 at the center frequency of 1.62GHz, and the conversion rate is 99.3%. Within the operating frequency band (1.61~1.63GHz), the inner axial ratio is less than 1.05, and the conversion rate reaches more than 99%.

[0059] Adjusting the angle between diaphragm-loaded circular polarizer 3 and diaphragm-loaded circular polarizer 2 to -45° (viewed from the input end, counterclockwise direction is positive), simulation in electromagnetic simulation software CST (2022) shows that the output is a right-handed TE11 circular polarization mode. The axial ratio is 1.04 at the center frequency of 1.62GHz, and the conversion rate is 99.2%. Within the operating frequency band (1.61~1.63GHz), the axial ratio is less than 1.07, and the conversion rate reaches more than 99%.

[0060] Adjusting the angle between diaphragm-loaded circular polarizer 3 and diaphragm-loaded circular polarizer 2 to 45° (viewed from the input end, counterclockwise direction is positive), simulation in electromagnetic simulation software CST (2022) shows that the output is in TE11 linear polarization mode, with a conversion rate of 99.4% at the center frequency of 1.62GHz, and a conversion rate of over 99% in the operating frequency band (1.61~1.63GHz).

[0061] Based on the scaling principle, the above dimensions are divided by the center frequency scaling factor q1, where q1 = f1 (GHz) / 1.62 (GHz), which gives the dimensions of each high-power microwave mode converter at the center frequency f1. As the center frequency f5 changes, the high-power microwave mode converters of the corresponding dimensions can achieve a mode conversion efficiency of 99% in the L, S, C, X, and Ku frequency bands. Under vacuum conditions, the system power capacity reaches the GW level.

[0062] As can be seen from the above results, this embodiment of the present invention can operate in a high-over-mode structure, and has the characteristics of high transmission efficiency and large power capacity. The above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the protection scope of the present invention.

Claims

1. A multi-arm diaphragm-loaded variable polarizer, characterized by The multi-arm diaphragm loading variable polarizer is prepared from metal material, comprises a multi-arm mode converter (1), two diaphragm loading circular polarizers, i.e., a first diaphragm loading circular polarizer (2) and a second diaphragm loading circular polarizer (3), the second diaphragm loading circular polarizer (3) is completely same as the first diaphragm loading circular polarizer (2); the multi-arm mode converter (1) is mechanically connected with the first diaphragm loading circular polarizer (2), the first diaphragm loading circular polarizer (2) is connected with the second diaphragm loading circular polarizer (3) through a rotary joint, the first diaphragm loading circular polarizer (2) and the second diaphragm loading circular polarizer (3) can coaxially rotate; the multi-arm mode converter (1) converts TM01 mode microwave into circularly polarized TE11 mode; the first diaphragm loading circular polarizer (2) converts the circularly polarized TE11 mode into linearly polarized TE11 mode; the second diaphragm loading circular polarizer (3) converts the linearly polarized TE11 mode into circularly polarized TE11 mode; The multi-arm mode converter (1) comprises a disc-shaped multi-path power division structure (11), N 180-degree E-plane bend waveguides (12) and a disc-shaped multi-path power combination structure (13), wherein the disc-shaped multi-path power division structure (11) is connected with the disc-shaped multi-path power combination structure (13) through the N 180-degree E-plane bend waveguides (12); The disc-shaped multi-path power division structure (11) comprises a first circular waveguide (111), a first inner conductor (113) and a first cylinder (112); the first cylinder (112) is open at one end and closed at the other end, and the first inner conductor (113) is coaxially nested in the cylinder near the closed end; one end of the first circular waveguide (111) is coaxially connected with the open end of the first cylinder (112) through a chamfer, the other end of the first circular waveguide (111) is a microwave input port, and the chamfer radius between the first circular waveguide (111) and the first cylinder (112) is D1 and the chamfer depth is H1; the first inner conductor (113) is in the shape of a circular truncated cone, and the circular truncated cone bottom of the first inner conductor (113) is tightly attached to the inner surface of the closed end of the first cylinder (112); The first circular waveguide (111) has a diameter D0 and a length H0, and a side wall thickness d; the first inner conductor (113) has a circular truncated cone with a top diameter D2, a bottom diameter D3, a height H2, and a thickness equal to d; the first cylinder (112) has an outer diameter D7, a length b, and a side wall thickness equal to d, and N rectangular waveguides, i.e., a first rectangular waveguide (1111), a second rectangular waveguide (1112), …, an nth rectangular waveguide (111n), and an Nth rectangular waveguide (111N), are uniformly extended from the side of the first cylinder (112), N is an even positive integer, and 1≤n≤N; the rectangular waveguide has a length a, a width equal to b, and a distance from the central axis of the first cylinder (112) equal to D7 / 2, and the N rectangular waveguides are connected to N 180-degree E-plane bend waveguides (12), respectively; the disc-shaped multi-path power division structure (11) divides TM01 mode microwave input from the port of the first circular waveguide (111) into N TE10 mode microwaves, and the N TE10 mode microwaves are transmitted to the disc-shaped multi-path power combination structure (13) through the radially distributed N 180-degree E-plane bend waveguides (12), respectively; N 180-degree E-plane bend waveguides (12) are used to connect the disc-shaped multi-path power division structure (11) and the disc-shaped multi-path power combination structure (13) and are angularly distributed with port sizes of a x b; the radial lengths of the N E-plane bend waveguides are different, the E-plane bending angle of the 180-degree E-plane bend waveguide (12) is 180 degrees, the inner wall chamfer radius is r3, the outer wall C chamfer radius is H3, and the inner wall thickness is equal to d; the microwave input ends of the 180-degree E-plane bend waveguides (12) are respectively connected to the N rectangular waveguides of the first cylinder (112); the N 180-degree E-plane bend waveguides (12) reverse the transmission direction of the TE 10 mode generated by the disc-shaped multi-path power division structure (11) and adjust the output phase of the TE 10 mode in the corresponding 180-degree E-plane bend waveguide (12) by the difference in the radial lengths of the N 180-degree E-plane bend waveguides (12). The disc-shaped multi-path power combination structure (13) is composed of a second circular waveguide (131), a second inner conductor (133), and a second cylinder (132), wherein the second cylinder (132) is open at one end and closed at the other end, and the second inner conductor (133) is coaxially nested inside the second circular waveguide (131) and the second cylinder (132); one end of the second circular waveguide (131) is a microwave output port; the second inner conductor (133) is composed of a cylindrical body (1333) and two circular truncated cone bodies, i.e., a first circular truncated cone body (1331) and a second circular truncated cone body (1332); the first circular truncated cone body (1331) of the second inner conductor (133) is tightly attached to the inner surface of the closed end of the second cylinder (132); The second circular waveguide (131) has a diameter equal to D0 and a length of H8, and a side wall thickness equal to d; the first circular frustum (1331) of the second inner conductor (133) has a bottom diameter of D4, a top diameter of D5, a height of H4, and a side wall thickness equal to d; the cylindrical body (1333) of the second inner conductor (133) has a diameter equal to D5, a length of H6, and a side wall thickness equal to d; the second circular frustum (1332) of the second inner conductor (133) has a bottom diameter equal to D5, a top diameter of D6, and a height equal to H8; the second cylinder (132) has a diameter equal to D7, a length equal to b, and a side wall thickness equal to d, and N second cylinder rectangular waveguides, i.e., a first second cylinder rectangular waveguide (1311), a second second cylinder rectangular waveguide (1312), …, an n-th second cylinder rectangular waveguide (131n), and an N-th second cylinder rectangular waveguide (131N), are uniformly arranged on the side of the second cylinder (132), the length of each of the second cylinder rectangular waveguides (1311), (1312), …, (131n), and (131N) is equal to a, the width of each of the second cylinder rectangular waveguides (1311), (1312), …, (131n), and (131N) is equal to b, and the distance from the center axis of the second cylinder (132) to each of the second cylinder rectangular waveguides (1311), (1312), …, (131n), and (131N) is D7 / 2, so as to be connected to the microwave output end of the N 180-degree E-plane bend waveguides (12); the disc-shaped multi-path power combining structure (13) combines the N rectangular TE10 mode microwaves of different phases output from the N 180-degree E-plane bend waveguides (12) to synthesize the microwaves, and outputs the synthesized microwaves through the output port of the second circular waveguide (131); the connection between the second circular waveguide (131) and the second cylinder (132) is chamfered in a C shape, and the chamfering depth is H5; the first circular frustum (1331) of the second inner conductor (133) and the second cylinder (132) are also chamfered in a C shape, and the chamfering depth is equal to H4; the connection between the cylindrical body (1333) of the second inner conductor (133) and the second circular frustum (1332) is chamfered with a chamfering radius of r4; and the top of the second inner conductor (133) is chamfered with a chamfering radius of r5. The first diaphragm loaded circular polarizer (2) is composed of a third circular waveguide (21), a first diaphragm (22) and a second diaphragm (23); the third circular waveguide (21) has an inner radius of R0, a length of L1 and a side wall thickness equal to d; the first diaphragm (22) and the second diaphragm (23) are symmetrically welded on the inner wall of the third circular waveguide (21) along the axis OO' of the third circular waveguide (21), the center position of the first diaphragm (22) is equal in distance to the input port and the output port; the first diaphragm (22) and the second diaphragm (23) have the same shape and are in the shape of a solid ship; the first diaphragm (22) is composed of a first left diaphragm slope (221), a first diaphragm middle section (222) and a first right diaphragm slope (223); the first left diaphragm slope (221) and the first right diaphragm slope (223) have the same shape, the first left diaphragm slope (221) is in the shape of a bevelled cylinder, i.e. a part having only three faces left after a solid cylinder is cut by a plane intersecting the end face and the side face of the cylinder, and the axial length of the first left diaphragm slope (221) is L2; the first diaphragm middle section (222) is in the shape of a horizontal cross section of a cylinder, i.e. a part having two end arcs as inferior arcs after a solid cylinder is cut by a plane intersecting the two end faces and parallel to the axis, the axial length of the first diaphragm middle section (222) is L3, and the thickness of the first diaphragm middle section (222) is h; the first right diaphragm slope (223) is connected to the first diaphragm middle section (222) and is chamfered at the connecting position, and the chamfer radius is r; the second diaphragm (23) is composed of a second left diaphragm slope (231), a second diaphragm middle section (232) and a second right diaphragm slope (233), wherein the second left diaphragm slope (231) and the second right diaphragm slope (233) have the same shape; the axial length of the second left diaphragm slope (231) is equal to L2, the axial length of the second diaphragm middle section (232) is equal to L3, and the thickness of the second diaphragm middle section (232) is equal to h; the second right diaphragm slope (233) is connected to the second diaphragm middle section (232) and is chamfered at the connecting position, and the chamfer radius is equal to r; the third circular waveguide (21) is the output waveguide of the first diaphragm loaded circular polarizer (2), the first diaphragm (22) and the second diaphragm (23) realize circular polarization by changing the propagation constant of electromagnetic waves in the direction perpendicular to the diaphragm; and the third circular waveguide (21) is mechanically connected to the multi-armed mode converter (1).

2. The multi-arm membrane patch loading variable polarizer of claim 1, wherein The number N of the rectangular waveguides extending from the side of the first cylinder (112) is greater than or equal to 6, the length b of the first cylinder (112) satisfies b < λ0 / 2, the outer diameter D7 of the first cylinder (112) is (1-2) x N x a / π, the length a of the rectangular waveguide satisfies λ0 / 2 < a < 3λ0 / 2, and λ0 is the wavelength of the input microwave in free space.

3. The multi-arm membrane patch loading variable polarizer of claim 1, wherein The 180-degree E-plane bent waveguide (12) has a height HA of 2-10 times the waveguide height b, the radial lengths of the N 180-degree E-plane bent waveguides (12) are R1, …, R n , respectively, and R1≥b, when n is greater than or equal to 2, N , respectively, and R1≥b, when n is greater than or equal to 2, λ0 is the wavelength of the input microwave in free space.

4. The multi-arm membrane patch loading variable polarizer of claim 1, wherein The diameter D0 of the first circular waveguide (111) satisfies D0≥4π / λ0 / 2.4048, λ0 is the wavelength of the input microwave in free space, and the side wall thickness d of the first circular waveguide (111) is 3-5 mm; the length H0 of the first circular waveguide (111) satisfies H0>λ0 / 4, and the length H8 of the second circular waveguide (131) satisfies H8>λ0 / 4.

5. The multi-arm membrane patch loading variable polarizer of any of claims 2-4, wherein The accurate value determination method of D1, H1, D2, D3, H2, R n , H3, D5, D6, H5, H6, D4 is: after a, b and D0, D7, HA are determined, through the electromagnetic simulation software HFSS, under the conditions of H0>λ0 / 4, H8>λ0 / 4, H2>0, H4>0, the transmission efficiency of microwave transmission to the output end of the multi-arm mode converter is greater than 99%, and the output phase TE 11 mode phase difference is 90 degrees, the accurate values of D1, H1, D2, D3, H2, R n , H3, D5, D6, H5, H6, D4 are obtained.

6. The multi-arm membrane patch loading variable polarizer of claim 1, wherein The accurate value determination method of the axial length L2 of the first left diaphragm ramp (221), the axial length L3 of the first diaphragm middle section (222) and the thickness h is as follows: the electromagnetic simulation software CST is used to calculate the cutoff wavelength λ c1 of the vertical component of the first diaphragm (22) under different conditions c2 , the cutoff wavelength λ 11 of the parallel component of the first diaphragm (22), so that L3(k1-k2)=π / 4, wherein k1 is the phase shift constant perpendicular to the first diaphragm middle section (222), and k2 is the phase shift constant parallel to the first diaphragm middle section (222), λ0 is the wavelength of the input microwave in free space, and the rough value of L3 is obtained from L3=π / 4 / (k1-k2); then the microwave is set to be input from the first circular waveguide of the diaphragm-loaded circular polarizer, output from the second circular waveguide and have a transmission efficiency greater than 99%; in addition, the amplitude of the two polarization components of the TE 11 mode under the circular polarization output mode is equal, and the phase difference is 90°, and the accurate values of the diaphragm parameters L2, L3 and h are obtained after optimization.

7. The multi-arm membrane patch loading variable polarizer of claim 1, wherein The metal material is aluminum.

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