Methods for improving and adjusting the isolation of power dividers

Abstract

The present invention discloses a method for improving and adjusting the isolation of a power divider, comprising: providing a plurality of parallel transmission line branches, the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, the second port is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, and each transmission line adopts a plurality of 1 / 4 wavelength conversion branches, a multi-section impedance conversion and other structures so that the radio frequency microwave signals of the plurality of transmission line branches are evenly distributed. The present invention also discloses the application of the method for improving and adjusting the isolation of a power divider in the impedance matching of a waveguide power divider connector. The present invention changes the wavelength and width of the transmission line of the internal circuit of the power divider, increases the multi-path symmetry, and is designed into an equally divided structure, thereby solving the inconvenience of installing isolation resistors in the high frequency band, suppressing the discontinuity caused by the accumulation of microwaves in the transmission of the microstrip line, improving the isolation performance of adjacent ports of the power divider, and also improving the measurement accuracy.

Description

Technical Field

[0001] The invention belongs to the field of communication microwaves, and in particular relates to a method for improving and adjusting the isolation of a power divider. Background Art

[0002] In daily communication, it is often necessary to distribute one signal to multiple branches, and each branch requires the same signal size, so power splitters are developed. There are many types of power splitters, such as one-to-two, one-to-three, one-to-four, etc. A power splitter is equivalent to a lossy three-port network.

[0003] Power dividers are widely used in RF microwaves. They divide a signal into two paths, and there is loss in the distribution process. In scalar network analyzer measurements, they divide the signal output by the signal source into two paths, one to the R receiver and the other to the A or B receiver to achieve ratio measurement.

[0004] The power divider is an important component in the microwave system, which is used to divide the transmission power into several paths and transmit it to different loads, or combine several paths of power into one path to obtain greater power. The performance of the microwave power divider, such as insertion loss, isolation and other indicators, will have a relatively large impact on the performance of the entire system.

[0005] The most common microwave power divider at present is a distributed parameter power divider using a microstrip line structure. However, the waveguide power divider has a small insertion loss, poor isolation, and a complicated manufacturing process. Summary of the invention

[0006] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0007] Still another object of the present invention is to provide a method for improving and adjusting the isolation of a power divider.

[0008] To this end, the technical solution provided by the present invention is:

[0009] A method for improving and adjusting the isolation of a power divider, comprising:

[0010] A plurality of parallel transmission line branches are provided, wherein the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, and the second port of each transmission line branch is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, and each transmission line adopts a plurality of 1 / 4 wavelength conversion branches, including structures such as multi-section impedance conversion, so that the radio frequency microwave signals of the two transmission line branches are evenly distributed.

[0011] Preferably, in the method for improving and adjusting the isolation of a power divider, a 1 / 4 wavelength microstrip line is used at the transmission line impedance converter port of each branch.

[0012] Preferably, in the method for improving and adjusting the isolation of a power divider, the plurality of parallel transmission line branches include 6 transmission line branches, the impedance in the branch is a complex impedance, and the branch has an impedance adjustment function.

[0013] Preferably, in the method for improving and adjusting the isolation of a power splitter, the one-to-six power splitter expansion structure comprises: one input port, six output ports, and the isolation between each output port is completed by the branch of the expansion structure;

[0014] After entering the input port, the signal is transmitted through multiple branch 1 / 4 wavelength microstrip lines. Considering that the transmission line has multiple turns and there is no continuous position on the transmission path, the target value is set, and the length and width of each section of the transmission line are determined by simulation software, while improving the working bandwidth.

[0015] Preferably, in the method for improving and adjusting the isolation of a power splitter, in the one-to-six power splitter expansion structure, the length of each branch is determined by 1 / 4 wavelength.

[0016] Preferably, in the method for improving and adjusting the isolation of the power divider, the signal at the input port of the power divider is fed to other ports through an integrated chip to achieve impedance matching, without jumps in the microwave transmission path, and grooves are added to the side and bottom surfaces of the 1 / 4 wavelength equivalent cross-section.

[0017] Preferably, in the method for improving and adjusting the isolation of a power divider, the integrated chip inside the power divider is an integrated circuit composed of a resistor, an inductor, and a capacitor, specifically: an integrated circuit formed by two resistors and a capacitor connected in series, and another capacitor and another resistor in parallel.

[0018] Preferably, in the method for improving and adjusting the isolation of the power divider, when the internal circuit of the power divider microstrip line is composed of two capacitors C and two inductors L, since the capacitors and inductors will present a pure resistance form at a certain frequency, the phase difference formed by the series-parallel connection between the two and the phase shift formed between the capacitive inductance and the multi-point grounding characteristics are used to offset the discontinuity of microwaves in the microstrip line transmission, thereby improving the isolation of the power divider, wherein:

[0019]

[0020] The method for improving and adjusting the isolation of a power divider is applied to impedance matching of a waveguide power divider connector. The waveguide power divider connector adopts two arc surfaces to form an S shape, the steps are multi-level high and low transformations, the arc surfaces and the steps are bilaterally symmetrical structures, and the impedance of the power divider input port and the impedance of the power divider output port are compensated.

[0021] A device for improving and adjusting the isolation of a power divider, comprising:

[0022] A plurality of parallel transmission line branches, the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, the second port of each transmission line branch is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, each transmission line adopts a plurality of 1 / 4 wavelength conversion branches, a multi-section impedance conversion and other structures, so that the radio frequency microwave signals of the two transmission line branches are evenly distributed, and a 1 / 4 wavelength microstrip line is adopted at the impedance converter port of each branch transmission line.

[0023] The present invention includes at least the following advantages:

[0024] The present invention improves the original method of using isolation resistors to reduce the isolation of power dividers. It uses multi-stage expansion, considers impedance matching during the process to perform multi-stage impedance transformation, uses multiple branches for compensation, and designs an equally divided structure with two or more paths on the output path, thereby solving the inconvenience of installing isolation resistors in the high frequency band.

[0025] The present invention improves the isolation performance of adjacent ports of the power divider and also improves the measurement accuracy by changing the internal structure of the power divider, changing the wavelength and width of the circuit board transmission line, and increasing the multi-path symmetry.

[0026] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a diagram of the expanded structure of a one-to-six power divider in one solution of the present invention.

[0028] Figure 2 This is a diagram of the internal impedance distribution of a power divider in one of the solutions of the present invention.

[0029] Figure 3 This is the isolation curve before the power divider structure is changed.

[0030] Figure 4 This is the isolation curve after the structure of the one-to-six power divider in one solution of the present invention is changed.

[0031] Figure 5 This is an equivalent cross-sectional diagram of a 1 / 4 wavelength line in one of the solutions of the present invention.

[0032] Figure 6 This is the internal circuit diagram of the 1 / 4 wavelength line in one of the solutions of the present invention.

[0033] Figure 7 This is an internal circuit diagram of a microstrip line of a power divider in one of the solutions of the present invention.

[0034] Figure 8 This is a diagram of the S-shaped impedance matching structure of a waveguide power divider connector in one of the solutions of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0036] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0037] It should be noted that in the description of the present invention, the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] The present invention provides a method for improving and adjusting the isolation of a power divider, comprising:

[0039] A plurality of parallel transmission line branches are provided, wherein the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, and the second port of each transmission line branch is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, and each transmission line adopts a plurality of 1 / 4 wavelength conversion branches, including structures such as multi-section impedance conversion, so that the radio frequency microwave signals of the two transmission line branches are evenly distributed.

[0040] In one solution of the present invention, preferably, a 1 / 4 wavelength microstrip line is used at the transmission line impedance transformer port of each branch.

[0041] In one of the solutions of the present invention, preferably, the plurality of parallel transmission line branches include 6 transmission line branches, the impedance in the branch is a complex impedance, and the branch has an impedance adjustment function.

[0042] In one solution of the present invention, as a preferred embodiment, the one-to-six power splitter expansion structure comprises: one input port, six output ports, and the isolation between each output port is completed by the branch of the expansion structure;

[0043] After entering the input port, the signal is transmitted through multiple 1 / 4 wavelength microstrip lines, the target value is set, and the length and width of each transmission line are determined by simulation software, while the working bandwidth is improved.

[0044] Due to the discontinuity of the microstrip line during the transmission process, microwaves accumulate during the transmission process. In order to increase the shielding inside the power divider, in one of the schemes of the present invention, as a preferred embodiment, the signal at the input port of the power divider is fed to other ports through an integrated chip to achieve impedance matching, without jumps in the microwave transmission path, and grooves are added to the side and bottom surfaces of the 1 / 4 wavelength equivalent cross-section.

[0045] Preferably, in the method for improving and adjusting the isolation of the power divider, the integrated chip is an integrated circuit composed of a resistor, an inductor, and a capacitor, specifically: an integrated circuit composed of two resistors and a capacitor connected in series, and another capacitor and another resistor in parallel.

[0046] The signal at the input port of the power divider is fed to other ports through an integrated chip composed of resistors, inductors, and capacitors to achieve impedance matching without jumps in the microwave transmission path. Figure 5 The structure shown in the figure adds grooves on the side and bottom of the 1 / 4 wavelength equivalent cross section to compensate for the discontinuity of microwaves in the microstrip line transmission process, thereby improving the isolation of the power divider. The groove width is 1 / 4 wavelength. Figure 5 .

[0047] Figure 6 The figure shows the internal circuit diagram of the 1 / 4 wavelength microstrip line, which consists of two resistors and a capacitor in series, and a capacitor and a resistor in parallel. It has reliable grounding, which suppresses the discontinuity of microwaves during transmission and reduces reflection losses, which is conducive to the smooth transmission of microwaves in the microstrip line and improves the isolation of the power divider.

[0048] R1=(1+K 2 )Z0

[0049]

[0050] In the above scheme, preferably, in the one-to-six power splitter expansion structure, the length of each branch is determined by 1 / 4 wavelength.

[0051] In the above scheme, as a preference, in the method for improving and adjusting the isolation of the power divider, the internal circuit of the power divider microstrip line ( Figure 7 ) is composed of two capacitors C and two inductors L. Since the capacitors and inductors will present pure resistance at a certain frequency, the phase difference formed by the series and parallel connection between the two and the phase shift formed between the capacitive and inductive properties, as well as the multi-point grounding characteristics, are used to offset the discontinuity of microwaves in microstrip line transmission, thereby improving the isolation of the power divider. Among them:

[0052]

[0053] Waveguide power dividers are important components in microwave and millimeter wave applications. Figure 8 The figure shows the impedance matching diagram of the waveguide power divider connector. According to the relevant basic theory, two arc surfaces are used to form an S shape, and the steps are multi-level high and low transformations. The arc surface and the steps are bilaterally symmetrical structures, which compensate the input port impedance of the power divider and the output port impedance of the power divider. The matching structure reduces reflections and achieves the effect of impedance matching, thereby improving the isolation of the power divider and facilitating mechanical processing. R1 and R2 are the arc radii.

[0054] A device for improving and adjusting the isolation of a power divider, comprising:

[0055] A plurality of parallel transmission line branches, the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, the second port of each transmission line branch is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, each transmission line adopts a plurality of 1 / 4 wavelength conversion branches, a multi-section impedance conversion and other structures, so that the radio frequency microwave signals of the two transmission line branches are evenly distributed, and a 1 / 4 wavelength microstrip line is adopted at the impedance converter port of each branch transmission line.

[0056] The present invention improves the isolation of adjacent ports of the power divider, reduces the crosstalk between the ports of the power divider, adopts multiple 1 / 4 wavelength conversion branches, multi-section impedance conversion and other structures, the working wavelength of the power divider is determined by the width and length of the internal transmission line, and the size is changed in length, height and height. A section of microstrip line is added at the impedance converter port of the two sections of the transmission line to replace the traditional chip capacitor and inductor, which improves the design accuracy of the power divider. The internal transmission line of the power divider adopts a microstrip line structure, see Figure 1 .

[0057] The original method of using isolation resistors to reduce the isolation of the power divider has been improved by using multi-stage expansion. During the process, impedance matching is considered for multi-stage impedance transformation. Multiple branches are used for compensation. It is designed into an equal-division structure with two or more output paths, which solves the inconvenience of installing isolation resistors in the high-frequency band.

[0058] The internal structure of the power divider is modeled through simulation software, which can both synthesize and distribute signals.

[0059] Add an impedance matching circuit inside the power divider. Figure 2 In the figure, the resistor R is used to achieve an even distribution between the two paths of the power divider, and two sections of transmission lines are used to achieve impedance transformation to ensure impedance matching between the two paths.

[0060] Figure 1This is the extended structure diagram of a one-to-six power splitter. P1 on the left side of the power splitter is the input port, and P2-P7 on the right side are the output ports. The isolation between the output ports is guaranteed by the branches of the extended structure.

[0061] After the signal enters the input port, it is transmitted through multiple 1 / 4 wavelength microstrip lines. Figure 3 The transmission line has many turns and no continuous positions on the transmission path. The target value is set and the length and width of each section of the transmission line are determined by simulation software, while the working bandwidth of the power divider is improved.

[0062] Figure 1 In the figure, each microstrip line represents a complex impedance, where Z1, Z2, and Z3 are input impedances, and Z=R+jx. Z is equivalent to a complex impedance, where R is a pure resistor, jx is a capacitor (represented by the letter c) and an inductor (represented by the letter L), and Z is a general term for resistors, capacitors, and inductors.

[0063]

[0064] Among them, Z0 is the characteristic impedance of the transmission line, and K is the output power ratio.

[0065] By adjusting the values ​​of resistance, capacitance and inductance, the isolation between adjacent ports of the power divider is optimized. In the specific implementation plan, the variable potentiometer above the resistance and capacitance is adjusted, and the input impedance Z value is changed.

[0066] According to the impedance transformation formula, Z is the complex impedance, which is converted from the reflection coefficient of each branch. The smaller Γ (reflection coefficient), the better the impedance matching of each branch, thereby improving the isolation of adjacent ports of the power divider.

[0067] In order for the power divider to have good isolation, the odd-mode input impedance, even-mode input impedance and port impedance must be equal. Figure 1 The parameters shown in must satisfy the following formula:

[0068] β is the transmission constant of the transmission line at frequency f, βl1 is the electrical angle of the transmission line at this frequency, and Z0 is the characteristic impedance of the transmission line:

[0069] Figure 1 middle,

[0070]

[0071] The length of each branch of the one-to-six structure is determined by 1 / 4 wavelength

[0072]

[0073] Figure 1 middle,

[0074]

[0075]

[0076] Figure 1 In the equation, the admittance matrix of the series resistor R is

[0077] Figure 3 and Figure 4 They are the isolation curves before and after the power divider structure is changed. It can be seen from the figure that the isolation index after the structure is changed is significantly better than that before the structure is changed.

[0078] The number of modules and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention are obvious to those skilled in the art.

[0079] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for improving and adjusting the isolation of a power divider, characterized in that: include: A plurality of parallel transmission line branches are provided, wherein the first port of each transmission line branch is electrically connected to the input port of the power divider circuit, and the second port of each transmission line branch is electrically connected to a plurality of output ports of the power divider circuit in a one-to-one correspondence, and each transmission line branch adopts a plurality of 1 / 4 wavelength conversion branches, including a multi-section impedance conversion structure, so that the radio frequency microwave signals of the plurality of parallel transmission line branches are evenly distributed, and a 1 / 4 wavelength microstrip line is adopted at each transmission line branch port; The plurality of parallel transmission line branches include 6 transmission line branches, the impedance in the branch is a complex impedance, and the branch has an impedance adjustment function; The one-to-six power splitter expansion structure includes: one input port, six output ports, the isolation between each output port is completed by the transmission line branch, and in the one-to-six power splitter expansion structure, the length of each transmission line branch is determined by 1 / 4 wavelength; The signal at the input port of the power divider is fed by an integrated chip to achieve impedance matching, without jumps on the microwave transmission path. At the same time, grooves are added to the side and bottom of the cross section of the 1 / 4 wavelength microstrip line. The integrated chip is an integrated circuit composed of a resistor, an inductor, and a capacitor, specifically: an integrated circuit formed by connecting two resistors and a capacitor in series, and another capacitor and another resistor in parallel.

2. The application of the method for improving and adjusting the isolation of a power divider as claimed in claim 1, characterized in that: The internal circuit of the power divider microstrip line is composed of two capacitors C and two inductors L. Since the capacitors and inductors will present pure resistance at a certain frequency, the phase difference formed by the series and parallel connection of the two and the phase shift formed between the capacitive and inductive properties and the multi-point grounding characteristics are used to offset the discontinuity of microwaves in microstrip line transmission, thereby improving the isolation of the power divider.

3. The method for improving and adjusting the isolation of a power divider as claimed in claim 1 is applied to impedance matching of a waveguide power divider connector, characterized in that: The waveguide power divider connector uses two arc surfaces to form an S shape, the steps are multi-level height changes, the arc surfaces and the steps are bilaterally symmetrical structures, and the impedance of the power divider input port is compensated with the impedance of the power divider output port.

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