A broadband and high isolation dual-mode power divider

Abstract

The present invention discloses a broadband and high-isolation dual-mode power divider, belonging to the technical field of microwave and millimeter-wave devices, having a planar symmetric structure, and comprising an E-plane input wide waveguide, a first E-plane output wide waveguide, an H-plane narrow waveguide, and a second E-plane output wide waveguide which are arranged in sequence to form a cross-shaped connection structure, and a matching structure is respectively arranged on the upper and lower bottom surfaces of the central connection region; for the matching structure arranged on the lower bottom surface, it includes a first step above the lower bottom surface, and a second step and a third step above the first step, one side of the third step is adjacent to the waveguide wall of the H-plane narrow waveguide, and the opposite side is adjacent to the second step. The present invention can not only realize the power distribution / synthesis of the TE 20 mode, but also realize the power distribution from the TE 10 mode to the TE 20 mode, and has the advantages of high power distribution efficiency, high port isolation, wide working bandwidth, compact structure and dual-mode multifunctional operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave and millimeter-wave devices, and particularly relates to a broadband and high-isolation dual-mode power divider. Background Art

[0002] Rectangular waveguides are widely used in microwave, millimeter-wave, and terahertz power distribution / synthesis circuits due to their low transmission loss, large power capacity, etc. The TE 10 mode is the dominant mode of rectangular waveguides, the most commonly used waveguide mode, and is applicable to various microwave and millimeter-wave circuits. The TE 20 mode is the second-highest mode of rectangular waveguides and is commonly used in power synthesis and high-order overmode slow-wave structures.

[0003] The TE 20 mode can be regarded as the parallel of two TE 10 modes with opposite-phase electric fields, and it is easy to distribute one TE 20 mode into two TE 10 modes through a waveguide or couple it into two quasi-TEM modes through a probe, thus having applications in the field of power synthesis. Currently, for power distribution / synthesis based on the TE 20 mode, the TE 10 mode is first converted into the TE 20 mode, and then a TE 20 mode power divider / combiner is used for power distribution / synthesis. The overall path is long and the structure is complex. In addition, in a power divider based on the TE 20 mode, except for the 3dB coupler type, the isolation of existing power dividers in the existing technology is relatively low. Summary of the Invention

[0004] The purpose of the present invention is to provide a broadband and high-isolation dual-mode power divider for the problems in the above-mentioned existing technology. It can not only achieve power distribution / synthesis of the TE 20 mode, but also achieve power distribution from the TE 10 mode to the TE 20 mode, that is, dual-mode power division, and has the advantages of a compact structure, low loss, high isolation, broadband operation, and dual-mode multi-functional operation.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A broadband and high-isolation dual-mode power divider, characterized in that it includes an E-plane input wide waveguide, a first E-plane output wide waveguide, an H-plane narrow waveguide, and a second E-plane output wide waveguide arranged in clockwise order, jointly forming a cross-shaped connection structure, and the E-plane input wide waveguide is orthogonal to the H-plane narrow waveguide;

[0007] The upper and lower bottom surfaces of the central connection region of the cross-shaped connection structure are respectively located in the planes where the upper and lower narrow side surfaces of the E-plane input wide waveguide, the first E-plane output wide waveguide, and the second E-plane output wide waveguide are located, and a matching structure is respectively arranged on the upper and lower bottom surfaces of the central connection region;

[0008] For the matching structure arranged on the lower bottom surface of the central connection region, it includes a first step located above the lower bottom surface, and a second step and a third step located above the first step; one side of the third step is adjacent to the waveguide wall of the H-plane narrow waveguide, and the opposite side is adjacent to the second step;

[0009] The dual-mode power divider is symmetric about the central dissection plane parallel to the narrow side surface of the E-plane input wide waveguide.

[0010] Further, the cross-sectional side length ratio of the E-plane input wide waveguide, the first E-plane output wide waveguide, and the second E-plane output wide waveguide is 4:1, and is used to transmit the TE 20 mode; the cross-sectional side length ratio of the H-plane narrow waveguide is 2:1, and is used to transmit the TE 20 mode in the same frequency band as the TE 10 mode.

[0011] Further, the E-plane input wide waveguide, the first E-plane output wide waveguide, the H-plane narrow waveguide, and the second E-plane output wide waveguide are all subjected to waveguide height reduction treatment at one end close to the central connection region; among them, the E-plane input wide waveguide symmetrically performs first-order stepped waveguide height reduction on the left and right wide side surfaces; the H-plane narrow waveguide symmetrically performs first-order stepped waveguide height reduction on the upper and lower wide side surfaces; the first E-plane output wide waveguide and the second E-plane output wide waveguide perform first-order linear gradient height reduction on the wide side surface on one side of the E-plane input wide waveguide.

[0012] Further, the length of the first step is greater than the sum of the lengths of the second step and the third step, and the height of the first step is one-eighth of the wavelength.

[0013] Further, the upper surface of the third step is located at 1 / 4 of the height between the upper and lower wide side surfaces after the height reduction of the H-plane narrow waveguide, the height of the second step is 1 / 5 - 1 / 8 of that of the third step, and the widths of the second step and the third step are 1 / 2 - 1 of that of the first step.

[0014] The working principle of the broadband high-isolation dual-mode power divider of the present invention is as follows:

[0015] When the TE 20 mode is input from the E-plane input wide waveguide, after passing through the central connection region, under the action of the upper and lower matching structures, the TE 20 mode will be equally divided into two paths of TE 20mode, respectively output from the first E-plane output wide waveguide and the second E-plane output wide waveguide. Since the E-plane input wide waveguide is orthogonal to the H-plane narrow waveguide, the TE input from the E-plane input wide waveguide 20 The mode is terminated in the H-plane narrow waveguide, and the H-plane narrow waveguide has almost no energy output;

[0016] When TE is input from the H-plane narrow waveguide 10 When the model passes through the central connected area, TE 10 The electric field of the mode will be coupled with equal amplitude and anti-phase by the upper and lower matching structures, and the coupled electric field will be distributed with equal amplitude and anti-phase to the first E-plane output wide waveguide and the second E-plane output wide waveguide respectively. Therefore, two equal amplitude and anti-phase TE are transmitted in the first E-plane output wide waveguide and the second E-plane output wide waveguide respectively. 10 Mode, constitute TE 20 mode; Since the E-plane input wide waveguide is orthogonal to the H-plane narrow waveguide, the TE input from the H-plane narrow waveguide 10 The mode is terminated in the E-plane input wide waveguide, and the E-plane input wide waveguide has almost no energy output, so the E-plane input wide waveguide and the H-plane narrow waveguide have extremely high isolation;

[0017] When TE 20 When the mode is input from the first E-surface output wide waveguide (second E-surface output wide waveguide), half of the power is input from the E-surface wide waveguide as TE 20 The other half of the power is coupled to the H-plane narrow waveguide by the upper and lower matching structures in the form of TE 10 The output is in the form of a mode, and there is almost no signal output in the second E-plane output wide waveguide (the first E-plane output wide waveguide), thereby achieving the effect of improving the isolation of the output port.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention proposes a broadband high-isolation dual-mode power divider, which can not only realize TE 20 Power distribution / synthesis of the mode, and TE 10 Model to TE 20 The power distribution of the two modes has the effect of dual-mode power division;

[0020] 2. The present invention realizes efficient power distribution and efficient coupling of branch unbalanced signals by the H-plane narrow waveguide by symmetrically arranging matching structures in the central connection area, thereby improving port isolation;

[0021] 3. The present invention reduces the characteristic impedance and improves the impedance matching bandwidth by performing waveguide height reduction processing on four waveguides respectively, thereby expanding the working bandwidth;

[0022] 4. The dual-mode power divider proposed by the present invention has a planar structure with a cross-connection, which is simple and compact, and has the advantages of low loss, high isolation, broadband operation, and dual-mode multi-functional operation. Description of the Drawings

[0023] Figure 1 It is a three-dimensional view of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0024] Figure 2 It is a top view of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0025] Figure 3 It is a front view of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0026] Figure 4 It is a right view of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0027] Figure 5 It is a partial three-dimensional view of the structure of the central connection area of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0028] Figure 6 It is a three-dimensional view of the internal waveguide path of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention;

[0029] Figure 7 For the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention, the electric field distribution diagram when inputting TE 20 mode from the E-plane input wide waveguide;

[0030] Figure 8 For the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention, the electric field distribution diagram when inputting TE 20 mode from the first E-plane output wide waveguide;

[0031] Figure 9 For the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention, the electric field distribution diagram when inputting TE 10 mode from the H-plane narrow waveguide;

[0032] Figure 10 It is the S-parameter simulation result diagram of the dual-mode power divider with broadband and high isolation provided in Embodiment 1 of the present invention applied to the WR-4.3 waveguide frequency band;

[0033] The descriptions of the marks in the drawings are as follows:

[0034] 101: E-plane input wide waveguide; 102: H-plane narrow waveguide; 103: First E-plane output wide waveguide; 104: Second

[0035] E-plane output wide waveguide; 20: matching structure disposed on the lower bottom surface of the central connection region; 201: third step; 202: second step; 203: first step. Detailed implementation

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Embodiment 1

[0038] This embodiment provides a dual-mode power divider with broadband and high isolation operating in the frequency band of 170 - 260 GHz. The structure is as Figures 1 to 6 shown, including an E-plane input wide waveguide 101, a first E-plane output wide waveguide 103, an H-plane narrow waveguide 102, and a second E-plane output wide waveguide 104 arranged in clockwise order, jointly forming a cross-shaped connection structure, and the E-plane input wide waveguide 101 is orthogonal to the H-plane narrow waveguide 102; the cross-sectional dimensions of the E-plane input wide waveguide 101, the first E-plane output wide waveguide 103, and the second E-plane output wide waveguide 104 are all 2.184 mm × 0.546 mm, for transmitting TE 20 mode; the H-plane narrow waveguide 102 is a standard WR-4.3 rectangular waveguide with a cross-sectional dimension of 1.092 mm × 0.546 mm, for transmitting TE 10 mode.

[0039] The upper and lower bottom surfaces of the central connection region of the cross-shaped connection structure are respectively located in the planes where the upper and lower narrow side surfaces of the E-plane input wide waveguide 101, the first E-plane output wide waveguide 103, and the second E-plane output wide waveguide 104 are located, and a matching structure is respectively arranged on the upper and lower bottom surfaces of the central connection region.

[0040] For the matching structure 20 disposed on the lower bottom surface of the central connection region, it includes a first step 203 located above the lower bottom surface, and a second step 202 and a third step 201 located above the first step 203; one side of the third step 201 is adjacent to the waveguide wall of the H-plane narrow waveguide 102, and the opposite side is adjacent to the second step 202.

[0041] The dual-mode power divider is symmetric about the central sectional plane of the E-plane input wide waveguide 101 parallel to the narrow side surface.

[0042] Furthermore, the E-plane input wide waveguide 101, the first E-plane output wide waveguide 103, the H-plane narrow waveguide 102, and the second E-plane output wide waveguide 104 are all subjected to waveguide height reduction at one end close to the central connection region. Among them, the E-plane input wide waveguide 101 symmetrically performs a first-order stepped waveguide height reduction on the left and right wide side faces. After the height reduction, the narrow side dimension is 0.43 mm, and the length of the height-reduced waveguide is 0.61 mm. The H-plane narrow waveguide 102 symmetrically performs a first-order stepped waveguide height reduction on the upper and lower wide side faces. After the height reduction, the narrow side dimension is 0.35 mm, and the length of the height-reduced waveguide is 0.36 mm. The first E-plane output wide waveguide 103 and the second E-plane output wide waveguide 104 perform a first-order linear tapered height reduction on the wide side face on one side of the E-plane input wide waveguide 101. After the height reduction, the narrow side dimension is 0.31 mm, the length of the height-reduced waveguide is 0.06 mm, and the linear taper length of the waveguide is 0.2 mm.

[0043] Furthermore, the length of the first step 203 is 0.7 mm, the width is 0.32 mm, and the height is 0.16 mm. The length of the third step 201 is 0.29 mm, the width is 0.15 mm, and the height is 0.84 mm. The length of the second step 202 is 0.28 mm, the width is 0.12 mm, and the height is 0.13 mm.

[0044] Furthermore, for ease of processing, all the inner angles of the dual-mode power divider are rounded with a radius of 0.1 mm.

[0045] It should be noted that in this embodiment, all length directions are along the signal transmission direction.

[0046] In this embodiment, a three-dimensional electromagnetic simulation software is used to accurately design the dimensions of the dual-mode power divider with broadband and high isolation. To facilitate verifying the performance of the dual-mode power divider proposed in this embodiment, it is applied to the WR-4.3 waveguide in the 170-260 GHz frequency band for simulation. When the TE 20 mode is input at the E-plane input wide waveguide 101, its electric field distribution is as Figure 7 shown. The TE 20 mode is equally divided and output from the first E-plane output wide waveguide 103 and the second E-plane output wide waveguide 104 respectively. When the TE 20 mode is input at the first E-plane output wide waveguide 103, its electric field distribution is as Figure 8 shown. There is no energy output at the opposite second E-plane output wide waveguide 104, indicating good isolation between the first E-plane output wide waveguide 103 and the second E-plane output wide waveguide 104. When the TE 10 mode is input at the H-plane narrow waveguide 102, its electric field distribution is as Figure 9 shown. The TE 20 mode is equally divided and output from the first E-plane output wide waveguide 103 and the second E-plane output wide waveguide 104 respectively. The numerical simulation results of this structure are as Figure 10As shown, in the range of 178 - 258 GHz, the return loss of the E-plane input wide waveguide 101 port exceeds 17 dB, the isolation from the H-plane narrow waveguide 102 port exceeds 52 dB, the return losses of the first E-plane output wide waveguide 103 port and the second E-plane output wide waveguide 104 port are greater than 20 dB, and the isolation between them exceeds 16 dB. In the range of 184 - 251 GHz, the return loss of the H-plane narrow waveguide 102 port exceeds 19 dB, and the relative bandwidth exceeds 32%, achieving broadband, high-isolation, and multi-mode power distribution.

[0047] In summary, the dual-mode power divider with broadband and high isolation proposed in this embodiment has four ports on the same plane, forming a cross structure, with opposite ports isolated from each other, and has the advantages of compact structure, low loss, high isolation, broadband operation, and dual-mode multi-functional operation.

[0048] The above embodiments only illustrate the principles and advantages of the present invention, rather than limiting the present invention. They are only for helping to understand the principles of the present invention. The protection scope of the present invention is not limited to the above configurations and embodiments. Those skilled in the art can make various other specific deformations and combinations without departing from the essence of the present invention, but still within the protection scope of the present invention.

Claims

1. A broadband high-isolation dual-mode power divider, characterized in that, it includes an E-plane input wide waveguide, a first E-plane output wide waveguide, an H-plane narrow waveguide, and a second E-plane output wide waveguide arranged in clockwise order, jointly forming a cross-shaped connection structure, and the E-plane input wide waveguide is orthogonal to the H-plane narrow waveguide; The E-plane input wide waveguide, the first E-plane output wide waveguide, the H-plane narrow waveguide, and the second E-plane output wide waveguide are all subjected to waveguide height reduction at one end close to the central connection region; The upper and lower bottom surfaces of the central connection region of the cross-shaped connection structure are respectively located in the planes where the upper and lower narrow side surfaces of the E-plane input wide waveguide, the first E-plane output wide waveguide, and the second E-plane output wide waveguide are located, and a matching structure is respectively arranged on the upper and lower bottom surfaces; For the matching structure arranged on the lower bottom surface, it includes a first step located above the lower bottom surface, and a second step and a third step located above the first step; one side of the third step is adjacent to the waveguide wall of the H-plane narrow waveguide, and the opposite side is adjacent to the second step; The dual-mode power divider is symmetric about the central section plane where the E-plane input wide waveguide is parallel to the narrow side surface.

2. The broadband high-isolation dual-mode power divider according to claim 1, characterized in that, The cross-sectional side length ratio of the E-plane input wide waveguide, the first E-plane output wide waveguide, and the second E-plane output wide waveguide is 4:1, which is used to transmit TE 20 mode; the cross-sectional side length ratio of the H-plane narrow waveguide is 2:1, which is used to transmit TE 20 mode in the same frequency band as the TE 10 mode.

3. The broadband high-isolation dual-mode power divider according to claim 1, characterized in that, The E-plane input wide waveguide symmetrically performs first-order stepped waveguide height reduction on the left and right wide side surfaces; the H-plane narrow waveguide symmetrically performs first-order stepped waveguide height reduction on the upper and lower wide side surfaces; the first E-plane output wide waveguide and the second E-plane output wide waveguide perform first-order linear tapered height reduction on the wide side surface on one side of the E-plane input wide waveguide.

4. The broadband high-isolation dual-mode power divider according to claim 3, characterized in that, The upper surface of the third step is located at 1 / 4 of the height between the upper and lower wide side surfaces after the height reduction of the H-plane narrow waveguide, the height of the second step is 1 / 5 to 1 / 8 of the third step, and the widths of the second step and the third step are 1 / 2 to 1 of the first step.

5. The broadband high-isolation dual-mode power divider according to claim 1, characterized in that, The length of the first step is greater than the sum of the lengths of the second step and the third step, and the height of the first step is one-eighth of the wavelength.

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