Rectangular waveguide-microstrip three-way power divider

Abstract

The rectangular waveguide-microstrip three-path power divider comprises a waveguide body and a microstrip circuit, the microstrip circuit is located in the waveguide body, the waveguide body is provided with a rectangular waveguide port and a shielding cavity, and a waveguide short-circuit surface is manufactured at the terminal of the rectangular waveguide port; the microstrip circuit comprises a dielectric substrate, fan-shaped probes are symmetrically arranged on the dielectric substrate, each fan-shaped probe is sequentially connected with an impedance conversion line, a low-impedance branch line and a first 50-ohm microstrip line, the low-impedance branch line is further connected with a high-impedance branch line, and the end of the high-impedance branch line is connected with a second 50-ohm microstrip line. After being input from the rectangular waveguide port, a microwave signal is efficiently coupled to the microstrip circuit under the combined action of the fan-shaped probe and the waveguide short-circuit surface; after impedance matching is carried out on signals through the impedance conversion lines, the signals are distributed to the low-impedance branch lines and the high-impedance branch lines, the signals distributed to the low-impedance branch lines are output from the first 50-ohm microstrip line, and the signals in the two high-impedance branch lines are output from the second 50-ohm microstrip line.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave devices, and particularly relates to a rectangular waveguide-microstrip three-way power divider. BACKGROUND

[0002] In the electromagnetic spectrum, electromagnetic waves with a frequency exceeding 300MHz are usually referred to as microwaves, and such electromagnetic waves play an important role in many fields such as communication systems, radar equipment, electronic countermeasures, telemetry and remote sensing, and industrial manufacturing. As one of the most widely used devices in microwave systems, a power divider has a bidirectional function: it can not only distribute a single microwave signal into two or more coherent signals, but also combine multiple coherent microwave signals into one output.

[0003] There are various circuit forms of power dividers, and common ones are Wilkinson bridge, Lange bridge, branch line bridge, T-junction, magic T, etc. According to the application requirements, various microwave transmission lines including microstrip line, stripline, coaxial line, CPW, SIW, rectangular waveguide, etc. can be used independently or in combination. The documents such as Design of Rectangular Waveguide to Microstrip Power Dividers and Their Application as Compact Rectangular Matching Terminations, A Waveguide Power Divider / Combiner Using Microstrip E-plane Dual-Probe Structure, Compact Planar Transmission-line Transition Direct-connecting from a Waveguide to Four Microstrip-lines report a type of mixed power divider of rectangular waveguide and microstrip line, in which the rectangular waveguide as the main port has high power capacity, and the microstrip line as the branch port is easy to integrate semiconductor devices. This type of power divider uses the structure design of inserting multiple microstrip probes into the waveguide at the same time, which realizes the functions of rectangular waveguide-microstrip transition and power distribution at one time. This integrated design not only makes the power division circuit more compact, but also effectively reduces the insertion loss. However, in order to ensure the consistency of the power distribution amplitude, the microstrip probes in the waveguide must strictly follow the principle of symmetrical distribution. This symmetry constraint results in that the number of branches of the rectangular waveguide-microstrip mixed power divider can only be configured in powers of 2 (such as 4, 8, 16, 32, etc.), which greatly limits the design flexibility of the power divider. SUMMARY

[0004] The application aims to solve the above problems, provide a symmetrical arrangement, high flexibility and break 2 n Rectangular waveguide-microstrip hybrid three-way power divider.

[0005] To solve the above technical problems, the technical scheme of the application is: a rectangular waveguide-microstrip three-way power divider, comprising a waveguide body and a microstrip circuit, the microstrip circuit is located in the waveguide body, the waveguide body is provided with a rectangular waveguide port and a shielding cavity, a waveguide short circuit surface is made at the terminal of the rectangular waveguide port; the microstrip circuit comprises a dielectric substrate, the dielectric substrate is provided with symmetrically arranged fan-shaped probes, each fan-shaped probe is sequentially connected with an impedance transformation line, a low-impedance branch line and a first 50Ω microstrip line, the low-impedance branch line is further connected with a high-impedance branch line, the end of the high-impedance branch line is connected with a second 50Ω microstrip line, the end of the second 50Ω microstrip line and the first 50Ω microstrip line is provided with a microstrip port, the impedance transformation line, the high-impedance branch line and the low-impedance branch line form a T-shaped joint structure with a power division ratio of 2:1, the two high-impedance branch lines and the second 50Ω microstrip line form a T-shaped joint with a power division ratio of 1:1; after the microwave signal is input from the rectangular waveguide port, it is efficiently coupled to the microstrip circuit under the joint action of the fan-shaped probe and the waveguide short circuit surface; after the signal is impedance matched through the impedance transformation line, it is distributed to the low-impedance branch line and the high-impedance branch line through the T-shaped joint with a power division ratio of 2:1, the signal distributed to the low-impedance branch line is finally output from the first 50Ω microstrip line on both sides of the circuit, at the same time, the signals in the two high-impedance branch lines are combined into one through the T-shaped joint with a power division ratio of 1:1, and are output from the second 50Ω microstrip line in the middle of the circuit.

[0006] Preferably, the low-impedance branch line and the first 50Ω microstrip line are equal in width and are connected through a 90° corner-cut microstrip line.

[0007] Preferably, the fan-shaped probe is a gradient structure, and the distance between the waveguide short circuit surface and the back of the fan-shaped probe is equal to about one-quarter of the waveguide wavelength.

[0008] Preferably, the line width of the low-impedance branch line is the same as that of the first 50Ω microstrip line, so its characteristic impedance is also 50Ω; in order to realize a power division ratio of 2:1, the characteristic impedance of the high-impedance branch line is designed to be about 100Ω; according to the impedance parallel characteristic of the microstrip T-shaped joint, the characteristic impedance of the combined end should be the parallel value of 50Ω and 100Ω, that is, about 33.3Ω; therefore, the role of the impedance transformation line is to match the impedance of the fan-shaped probe to 33.3Ω.

[0009] Preferably, the return wave of the rectangular waveguide port is lower than-18.5dB, and the transmission amplitudes of the three microstrip ports are basically equal, within the range of-4.78±0.1dB.

[0010] Preferably, the transmission phases of the three microstrip ports are basically consistent, with an error of less than ±1°.

[0011] Preferably, the microwave signal is input from a rectangular waveguide port, and is divided into three signals of equal amplitude and same phase, and then output from microstrip ports.

[0012] Preferably, the fan-shaped probes are supported by a dielectric substrate and suspended in the rectangular waveguide port of the waveguide body, and the impedance transformation line, the low-impedance branch line and the first 50Ω microstrip line are located in the shielded cavity.

[0013] The present application has the following advantages:

[0014] The rectangular waveguide-microstrip three-way power divider provided by the present application successfully constructs three microstrip output ports by re-distributing and combining the waveguide-microstrip double-probe circuit. This design breaks through the limitation of traditional waveguide-microstrip power dividers that can only realize two-way power division, and makes the design of the number of power division in power synthesis application more flexible. n BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a top view of a rectangular waveguide-microstrip three-way power divider of the present application;

[0016] Figure 2 is a "I-I" cross-sectional view of the present application; Figure 1

[0017] Figure 3 is a microstrip circuit layout in the present application; Figure 1

[0018] Figure 4 is a port return and port transmission amplitude effect diagram of the present application;

[0019] Figure 5 is a port transmission phase consistency effect diagram of the present application.

[0020] Reference signs: 1, waveguide body; 2, microstrip circuit; 101, rectangular waveguide port; 102, waveguide short circuit surface; 103, shielded cavity; 201, microstrip port; 202, dielectric substrate; 203, fan-shaped probe; 204, impedance transformation line; 205, high-impedance branch line; 206, low-impedance branch line; 207, first 50Ω microstrip line; 208, second 50Ω microstrip line. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with the drawings and specific embodiments:

[0022] As Figures 1 to 5 ​​​As shown, the rectangular waveguide-microstrip three-way power divider provided by the application is characterized in that it comprises a waveguide body 1 and a microstrip circuit 2, the microstrip circuit 2 is located in the waveguide body 1, the waveguide body 1 is provided with a rectangular waveguide port 101 and a shielding cavity 103, and a waveguide short circuit surface 102 is made at the terminal end of the rectangular waveguide port 101. The microstrip circuit 2 comprises a dielectric substrate 202, the dielectric substrate 202 is provided with symmetrically arranged fan-shaped probes 203, each fan-shaped probe 203 is sequentially connected with an impedance transformation line 204, a low-impedance branch line 206 and a first 50Ω microstrip line 207, the low-impedance branch line 206 is further connected with a high-impedance branch line 205, the end of the high-impedance branch line 205 is connected with a second 50Ω microstrip line 208, the end of the second 50Ω microstrip line 208 and the end of the first 50Ω microstrip line 207 are provided with microstrip ports 201, the impedance transformation line 204, the high-impedance branch line 205 and the low-impedance branch line 206 form a T-shaped joint structure with a power division ratio of 2:1, and the two high-impedance branch lines 205 and the second 50Ω microstrip line 208 form a T-shaped joint with a power division ratio of 1:1. After the microwave signal is input from the rectangular waveguide port 101, it is efficiently coupled to the microstrip circuit 2 under the joint action of the fan-shaped probes 203 and the waveguide short circuit surface 102. After the signal is impedance-matched through the impedance transformation line 204, it is distributed to the low-impedance branch line 206 and the high-impedance branch line 205 through the T-shaped joint with a power division ratio of 2:1, and the signal distributed to the low-impedance branch line 206 is finally output from the first 50Ω microstrip line 207 on both sides of the circuit, at the same time, the signals in the two high-impedance branch lines 205 are combined into one through the T-shaped joint with a power division ratio of 1:1, and are output from the second 50Ω microstrip line 208 in the middle of the circuit.

[0023] In the embodiment, the microstrip circuit 2 is adhered to the waveguide body 1 by using conductive glue. The fan-shaped probes 203 of the microstrip circuit 2 are supported by the dielectric substrate 202 and suspended in the rectangular waveguide port 101 of the waveguide body 1, and the rest of the microstrip circuit 2 is located in the shielding cavity 103 of the waveguide body 1.

[0024] The low-impedance branch line 206 and the first 50Ω microstrip line 207 are equal in width, and the two are connected through a 90° angle-cut microstrip line. The second 50Ω microstrip line 208 and the first 50Ω microstrip line 207 are the same in structure.

[0025] The fan-shaped probe 203 is a gradient structure, and the distance between the waveguide short circuit surface 102 and the back of the fan-shaped probe 203 is equal to about one-quarter of the waveguide wavelength.

[0026] The line width of the low-impedance branch line 206 is the same as that of the first 50Ω microstrip line 207, so its characteristic impedance is also 50Ω. In order to achieve a power division ratio of 2:1, the characteristic impedance of the high-impedance branch line 205 is designed to be about 100Ω; according to the impedance parallel characteristic of the microstrip T-junction, the characteristic impedance of the combined end should be the parallel value of 50Ω and 100Ω, i.e. about 33.3Ω. Therefore, the role of the impedance transformation line 204 is to match the impedance of the fan-shaped probe 203 to 33.3Ω.

[0027] The echo of the rectangular waveguide port 101 is below -18.5dB, and the transmission amplitudes of the three microstrip ports 201 are substantially equal, within the range of -4.78±0.1dB. The transmission phases of the three microstrip ports 201 are substantially consistent, with an error of less than ±1°.

[0028] The microwave signal is input from the rectangular waveguide port, and is divided into three signals of equal amplitude and in phase, and then output from the microstrip ports 201.

[0029] The fan-shaped probe 203 is supported by the dielectric substrate 202 and suspended in the rectangular waveguide port 101 of the waveguide body 1, and the impedance transformation line 204, the low-impedance branch line 206 and the first 50Ω microstrip line 207 are located in the shielded cavity 103.

[0030] In order to understand the working principle of the present application, the working process of the present application is described again:

[0031] The microwave signal is input from the rectangular waveguide port 101, and under the joint action of the fan-shaped probe 203 and the waveguide short-circuit surface 102, it is coupled to the microstrip circuit 2 with high efficiency. After impedance matching by the impedance transformation line 204, the signal is distributed to the low-impedance branch line 206 and the high-impedance branch line 205 through a T-junction with a power division ratio of 2:1. Among them, the low-impedance branch line 206 is the same width as the first 50Ω microstrip line 207, and the two are connected through a 90° corner-cut microstrip line, and the signal is finally output from the first 50Ω microstrip line 207 on both sides of the circuit. At the same time, the signals in the two high-impedance branch lines 205 are combined into one through a T-junction with a power division ratio of 1:1, and are output from the second 50Ω microstrip line 208 in the middle of the circuit.

[0032] Those skilled in the art will appreciate that the embodiments described herein are intended to aid the reader in understanding the principles of the present application, and should be understood as not limiting the scope of protection of the present application to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations according to the technical inspiration disclosed in the present application without departing from the essence of the present application, and these modifications and combinations are still within the scope of protection of the present application.

Claims

1. A rectangular waveguide-microstrip three-way power divider, characterized by: The application relates to a waveguide device, which comprises a waveguide body (1) and a microstrip circuit (2), the microstrip circuit (2) being arranged in the waveguide body (1), the waveguide body (1) being provided with a rectangular waveguide port (101) and a shielded cavity (103), a waveguide short-circuit surface (102) being arranged at the terminal end of the rectangular waveguide port (101); the microstrip circuit (2) comprises a dielectric substrate (202), the dielectric substrate (202) being provided with symmetrically arranged fan-shaped probes (203), each fan-shaped probe (203) being sequentially connected with an impedance transformation line (204), a low-impedance branch line (206) and a first 50-ohm microstrip line (207), the low-impedance branch line (206) being further connected with a high-impedance branch line (205), the end of the high-impedance branch line (205) being connected with a second 50-ohm microstrip line (208), the end of the second 50-ohm microstrip line (208) and the end of the first 50-ohm microstrip line (207) being provided with microstrip ports (201), the impedance transformation line (204), the high-impedance branch line (205) and the low-impedance branch line (206) form a T-shaped joint structure with a power division ratio of 2:1, the two high-impedance branch lines (205) and the second 50-ohm microstrip line (208) form a T-shaped joint with a power division ratio of 1:1; after a microwave signal is input from the rectangular waveguide port (101), the microwave signal is efficiently coupled to the microstrip circuit (2) under the joint action of the fan-shaped probes (203) and the waveguide short-circuit surface (102); after the signal is impedance-matched by the impedance transformation line (204), the signal is distributed to the low-impedance branch line (206) and the high-impedance branch line (205) through the T-shaped joint with a power division ratio of 2:1, the signal distributed to the low-impedance branch line (206) is finally output from the first 50-ohm microstrip line (207) on both sides of the circuit, meanwhile, the signals in the two high-impedance branch lines (205) are combined into one through the T-shaped joint with a power division ratio of 1:1, and are output from the second 50-ohm microstrip line (208) in the middle of the circuit.

2. The rectangular waveguide-microstrip three-way power divider according to claim 1, characterized in that: The low-impedance branch line (206) and the first 50-ohm microstrip line (207) are equal in width, and the two are connected through a 90-degree angle-cut microstrip line.

3. The rectangular waveguide-microstrip three-way power divider according to claim 1, characterized in that: The fan-shaped probe (203) is a gradient structure, and the distance between the waveguide short-circuit surface (102) and the back of the fan-shaped probe (203) is equal to about one-quarter of the waveguide wavelength.

4. The rectangular waveguide-microstrip three-way power divider of claim 1, wherein: The line width of the low-impedance branch line (206) is the same as that of the first 50-ohm microstrip line (207), and therefore the characteristic impedance of the low-impedance branch line (206) is also 50 ohm; in order to realize a power division ratio of 2:1, the characteristic impedance of the high-impedance branch line (205) is designed to be about 100 ohm; according to the impedance parallel characteristic of the microstrip T-shaped joint, the characteristic impedance of the combined end should be the parallel value of 50 ohm and 100 ohm, i.e. about 33.3 ohm; therefore, the role of the impedance transformation line (204) is to match the impedance of the fan-shaped probe (203) to 33.3 ohm.

5. The rectangular waveguide-microstrip three-way power divider of claim 1, wherein: The echo of the rectangular waveguide port (101) is lower than -18.5 dB, and the transmission amplitudes of the three microstrip ports (201) are basically equal, within the range of -4.78+ / -0.1 dB.

6. The rectangular waveguide-microstrip three-way power divider of claim 1, wherein: The transmission phases of the three microstrip ports (201) are basically consistent, with an error of less than + / -1 degree.

7. The rectangular waveguide-microstrip three-way power divider of claim 1, wherein: The microwave signal is input from a rectangular waveguide port, divided into three signals with equal amplitude and same phase, and then output from a microstrip port (201).

8. The rectangular waveguide-microstrip three-way power divider of claim 1, wherein: The fan-shaped probe (203) is supported by a dielectric substrate (202) and suspended in the rectangular waveguide port (101) of the waveguide body (1), and the impedance transformation line (204), the low-impedance branch line (206) and the first 50Ω microstrip line (207) are located in the shielding cavity (103).

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