CN115966876A - Waveguide adjustable coupler and adjusting method thereof - Google Patents

Abstract

The application discloses a waveguide adjustable coupler and an adjusting method thereof, and belongs to the field of microwaves. The coupler adopts two back-to-back waveguide bridges, realizes adjustable coupling quantity of the waveguide coupler in a mode of matching with a tuning screw to tune a phase, can continuously adjust the coupling quantity, and can ensure better echo characteristic and isolation characteristic at the same time; the tuning position of the tuning screw is at the position of the hollow waveguide, and the size space is large, so that the tuning screw can work in a millimeter wave frequency band; furthermore, the waveguide is split from the E surface, the narrow edge of the waveguide is provided with a threaded hole, and the waveguide is arranged on the front surface of a product, so that the debugging and the production and the manufacturing are convenient.

Description

Waveguide adjustable coupler and adjusting method thereof

Technical Field

The application relates to the field of microwaves, in particular to a waveguide adjustable coupler and an adjusting method thereof.

Background

The waveguide has the characteristics of low loss and high power capacity, and is widely applied to various microwave and millimeter wave communication and radar systems. In the millimeter wave frequency band and the E wave band, the requirement on the coupling quantity of the product is very small, such as-20 dB, and the requirement on the precision of the coupling quantity is higher, the coupling window of the waveguide coupler is very small, the coupling quantity is difficult to ensure by completely depending on machining, and the product with the requirement is difficult to produce and manufacture.

The mode that the tuning screw is adjustable is adopted to compensate the machining error, and the mode is a reliable mode for realizing the products. Most of the existing waveguide adjustable couplers adopt a mode of adjusting the size of a coupling window by using a screw to realize adjustable coupling amount, for example, the technical scheme introduced in patent No. CN201922254021.7, but when the working frequency band is in the millimeter wave frequency band, the size of the coupling window is small, and a tuning screw cannot be put in the coupling window, so that the method is suitable for being applied to the frequency band with lower frequency but not suitable for the millimeter wave frequency band. Meanwhile, the method is adopted to adjust the coupling window, the influence on the echo and the isolation of the coupled device is large, and a good isolation characteristic is difficult to ensure in a tuning range.

Therefore, it is a key to solve the above problems to provide a coupler coupling amount tuning method.

Disclosure of Invention

The invention provides a waveguide adjustable coupler and an adjusting method thereof. For solving the above-mentioned problems. The technical scheme is as follows:

according to an aspect of the present application, there is provided a waveguide tunable coupler, the coupler comprising: the tuning screw is used for tuning the coupling degree;

the coupling coordination structure is designed into two back-to-back 90-degree 3dB waveguide bridges which are respectively a first waveguide bridge and a second waveguide bridge, the first waveguide bridge and the second waveguide bridge are connected through a first straight waveguide and a second straight waveguide, and the first straight waveguide is provided with a tuning screw;

the first waveguide bridge is provided with an input waveguide port, and the second waveguide bridge is provided with an output waveguide port.

Optionally, the metal cavity consists of a lower cavity and an upper cavity, and the lower cavity and the upper cavity are buckled and fastened through screws; the tuning screw is located on the surface of the upper cavity.

Optionally, the first straight waveguide is provided with a screw adjusting hole position, and the screw adjusting hole position is used for accommodating a tuning screw.

According to another aspect of the present application, there is provided a waveguide tunable coupler adjusting method for the waveguide tunable coupler of the above aspect, the method comprising:

inputting a microwave signal through an input waveguide port;

adjusting the tuning screw to set the current phase shift to 90 degrees;

under the condition of 90-degree phase shift, the microwave signal is divided into a first signal and a second signal through a first waveguide bridge, the amplitudes of the first signal and the second signal are equal, and the phase difference is 90 degrees;

the first signal is input to the second waveguide bridge through the first straight waveguide, while the second signal is input to the second waveguide bridge through the second straight waveguide, where the first signal and the second signal are combined.

Optionally, the method further comprises:

adjusting the tuning screw to set the current phase shift to 0 degrees;

at a phase shift of 0 degrees, the microwave signal is input to the second waveguide bridge through the first straight waveguide, where no signal is input.

Optionally, the method further comprises:

adjusting the tuning screw to set the current phase shift to 180 degrees;

the microwave signal is input to the second waveguide bridge through a second straight waveguide, with no signal input at the first straight waveguide, at a phase shift of 180 degrees.

In another aspect, a computer-readable storage medium is provided that stores at least one instruction for execution by a processor to implement the waveguide adjustable coupler adjustment method of the above aspect.

The invention provides a waveguide adjustable coupler which is particularly suitable for the field of microwaves. The coupling quantity of the waveguide coupler can be adjusted by adopting two back-to-back waveguide bridges and matching with a mode of tuning the phase by a tuning screw, the coupling quantity can be continuously adjusted, and meanwhile, better echo characteristics and isolation characteristics can be ensured; the tuning position of the tuning screw is at the empty waveguide, is not a coupling window of the coupler, and has larger size space, so that the tuning screw can work in a millimeter wave frequency band; furthermore, the waveguide is split from the E surface, the narrow edge of the waveguide is provided with a threaded hole, and the waveguide is arranged on the front surface of a product, so that the debugging and the production and the manufacturing are convenient.

Drawings

FIG. 1 shows a product outline of an E-band waveguide tunable coupler;

FIG. 2 shows a schematic diagram of a waveguide tunable coupler;

fig. 3 illustrates an internal structural view of the waveguide tunable coupler.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Reference herein to "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Referring to fig. 1 to 3, fig. 1 shows a product outline of an E-band waveguide tunable coupler, fig. 2 shows a schematic diagram of the waveguide tunable coupler, and fig. 3 shows an internal structure diagram of the waveguide tunable coupler.

In one possible implementation, the present embodiment is schematically illustrated with a tuning screw of type M1.2, a first straight waveguide and a second straight waveguide of type WR-12 standard rectangular waveguides, and a waveguide tunable coupler operating in the E band frequency band.

As shown in fig. 1, the coupler includes a metal cavity, a tuning screw for tuning the degree of coupling, and a coupling coordination structure (shown in fig. 3) located within the metal cavity, the tuning screw being labeled as number 3 in fig. 1. The whole product comprises two metal cavities separated from the section of the E surface.

The coupling coordination structure is designed as two oppositely facing 90 degree 3dB waveguide bridges, a first waveguide bridge and a second waveguide bridge, respectively, which are labeled Hybrid in fig. 2, the first waveguide bridge is labeled number 1 in fig. 3, and the second waveguide bridge is labeled number 2 in fig. 3.

The first waveguide bridge and the second waveguide bridge are connected by a first straight waveguide, which houses the tuning screw, and a second straight waveguide, which is numbered 3 in fig. 3 and 4 in fig. 3.

An input waveguide port is provided at the first waveguide bridge and an output waveguide port is provided at the second waveguide bridge, the input waveguide port being numbered 5 in fig. 3 and the output waveguide port being numbered 6 in fig. 3.

Optionally, as shown in fig. 1, the metal cavity is composed of a lower cavity and an upper cavity, the lower cavity and the upper cavity are buckled and fastened by screws, the tuning screws are located on the surface of the upper cavity, the lower cavity is numbered 1 in fig. 1, and the upper cavity is numbered 2 in fig. 1.

Optionally, as shown in fig. 3, the first straight waveguide is provided with a tuning screw hole position, the tuning screw hole position is used for accommodating a tuning screw, and the tuning screw hole position is numbered 7 in fig. 3.

Further describing fig. 3, fig. 3 is an internal structure diagram of the waveguide tunable coupler, in which 1 is a first waveguide 3dB bridge; 2 is a second waveguide 3dB bridge; 3 straight waveguide with phase tuning screw; 4 is a straight waveguide without phase tuning screws; the two back-to-back bridges are connected by straight waveguides marked 3 and 4; the lengths of the straight waveguides marked 3 and 4 are consistent in principle, but inconsistent lengths can also realize the function of adjusting the coupling quantity. 5 and 6 are input and output waveguide ports; reference numeral 7 denotes tuning screw holes for tuning the phase, one tuning screw being placed in each tuning screw hole. If the tuning screw insertion control is performed, the tuning screw hole is completely closed, and the phase is shifted to a certain level. The WR-12 standard rectangular waveguide is fitted with M1.2 tuning screws, each of which is capable of being shifted approximately 3 degrees in phase.

It was found experimentally that 90 degrees, approximately 30 tuning screws, are required to complete the signal from no output to-3 dB output at one port. The spacing of all these tuning screws is about one wavelength of the operating frequency, which keeps the echo at a good level during the tuning phase.

In summary, the present invention provides a waveguide tunable coupler, which is particularly suitable for the microwave field. The coupling quantity of the waveguide coupler can be adjusted by adopting two back-to-back waveguide bridges and matching with a mode of tuning the phase by a tuning screw, the coupling quantity can be continuously adjusted, and meanwhile, better echo characteristics and isolation characteristics can be ensured; the tuning position of the tuning screw is at the empty waveguide, which is not the coupling window of the coupler, and the size space is larger, so that the tunable waveguide coupler can work in a millimeter wave frequency band; furthermore, the waveguide is split from the E surface, the narrow edge of the waveguide is provided with a threaded hole, and the waveguide is arranged on the front surface of a product, so that the waveguide is convenient to debug and is convenient to produce and manufacture.

Further to fig. 2, fig. 2 is a schematic diagram of the tunable coupler comprising two back-to-back 90 degree 3dB waveguide bridges with a phase shifter (implemented by tuning screws) inserted in one of the transmission lines connecting the two bridges. According to the microwave network principle, a microwave signal is input from P1, and the signal is divided into two paths of signals with equal amplitude and 90-degree phase difference through a first electric bridge. The two signals are respectively input to the second electric bridge through two transmission lines for synthesis. When the phase shift of the phase shifter is 0 degree, the signal is completely output from the P2 port, and no signal is output from the P3 port; when the phase shifter is shifted by 180 degrees, the signal is completely output from the P3 port, and no signal is output from the P2 port; when the phase shifter is phase-shifted by 90 degrees, signals are output from the P2 port and the P3 port with equal amplitude; therefore, as long as the phase shift of the phase shifter is controlled, the amplitude of the signal output from which port can be controlled, and the adjustable coupling amount is realized. The isolation between the P2 port and the P3 port is not changed by the phase change of the phase shifter, so that the coupling amount can be adjusted and simultaneously the good isolation characteristic can be kept.

Therefore, a waveguide tunable coupler adjusting method can be obtained, and the method is used for the waveguide tunable coupler provided in the above embodiment as an example, and the method includes:

step one, inputting a microwave signal through an input waveguide port.

And step two, adjusting the tuning screw to set the current phase shift to be 90 degrees.

And thirdly, under the condition of 90-degree phase shift, dividing the microwave signal into a first signal and a second signal through the first waveguide bridge, wherein the first signal and the second signal are equal in amplitude and 90-degree in phase difference.

And fourthly, inputting the first signal to the second waveguide bridge through the first straight waveguide, and simultaneously inputting the second signal to the second waveguide bridge through the second straight waveguide, wherein the first signal and the second signal are synthesized at the second waveguide bridge.

In addition, other special phase shifting cases are also included.

In one possible embodiment, adjusting the tuning screw sets the current phase shift to 0 degrees; at a phase shift of 0 degrees, the microwave signal is input to the second waveguide bridge through the first straight waveguide, where no signal is input.

In another possible embodiment, adjusting the tuning screw sets the current phase shift to 180 degrees;

the microwave signal is input to the second waveguide bridge through the second straight waveguide with no signal input at the first straight waveguide, at a phase shift of 180 degrees.

In conclusion, the phase in the straight waveguide is adjusted by deep depth, so that the coupling quantity is continuously adjustable. Different from the mode of directly adjusting the size of the coupling window and the phase, the adjustment of the coupling amount is insensitive to the depth of the screw, each adjusting method only has micro-tuning to the coupling amount, which is important in the millimeter wave frequency band, so that the coupling amount can be accurately controlled; in addition, the tuning is adjusted in the narrow-side threaded hole of the waveguide, full-band phase shifting is achieved, and in the whole frequency band range, the phase of each frequency adjustment is basically kept consistent, so that the whole frequency band range can be guaranteed, the adjusted coupling amount is basically consistent, and the coupling amount is guaranteed to have better flatness.

The present invention also provides a computer readable medium having at least one instruction stored thereon, the at least one instruction being loaded and executed by a processor to implement the waveguide tunable coupler tuning method of the various embodiments described above.

The present application is intended to cover various modifications, alternatives, and equivalents, which may be included within the spirit and scope of the present application.

Claims (6)

1. A waveguide tunable coupler, the coupler comprising: the tuning screw is used for tuning the coupling degree;

the coupling coordination structure is designed into two back-to-back 90-degree 3dB waveguide bridges which are respectively a first waveguide bridge and a second waveguide bridge, the first waveguide bridge and the second waveguide bridge are connected through a first straight waveguide and a second straight waveguide, and the first straight waveguide is provided with a tuning screw;

the first waveguide bridge is provided with an input waveguide port, and the second waveguide bridge is provided with an output waveguide port.

2. The waveguide tunable coupler according to claim 1,

the metal cavity consists of a lower cavity and an upper cavity, and the lower cavity and the upper cavity are buckled and fastened through screws; the tuning screw is located on the surface of the upper cavity.

3. The waveguide tunable coupler of claim 1, wherein the first straight waveguide is provided with tuning screw holes for receiving tuning screws.

4. A method of tuning a waveguide tunable coupler, the method being used in the waveguide tunable coupler of any one of claims 1 to 6, the method comprising:

inputting a microwave signal through an input waveguide port;

adjusting the tuning screw to set the current phase shift to 90 degrees;

under the phase shift of 90 degrees, the microwave signal is divided into a first signal and a second signal through a first waveguide bridge, the amplitudes of the first signal and the second signal are equal, and the phase difference is 90 degrees;

the first signal is input to the second waveguide bridge through the first straight waveguide, while the second signal is input to the second waveguide bridge through the second straight waveguide, where the first signal and the second signal are combined.

5. The method of claim 4, wherein the method further comprises:

adjusting the tuning screw to set the current phase shift to 0 degrees;

at a phase shift of 0 degrees, the microwave signal is input to the second waveguide bridge through the first straight waveguide, where no signal is input.

6. The method of claim 4, wherein the method further comprises:

adjusting the tuning screw to set the current phase shift to 180 degrees;

the microwave signal is input to the second waveguide bridge through the second straight waveguide with no signal input at the first straight waveguide, at a phase shift of 180 degrees.

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