Balanced non-reflection filtering power divider

Abstract

The invention discloses a balanced type non-reflection filtering power divider which is composed of transmission lines TL1 and TL2, three-line coupling lines TCL1 and TCL2, half-wavelength open circuit branches TL5 and TL6, half-wavelength transmission lines TLc1 and TLc2, an absorption-isolation-common mode rejection composite network, a balanced type input port P1 + / P1-and two balanced type output ports P2 + / P2-and P3 + / P3-. The absorption-isolation-common mode rejection composite network is composed of two groups of branch strings with the same structure but different parameters, and each branch string is composed of two quarter-wavelength transmission lines and two resistors which are connected in series. The absorption-isolation-common-mode rejection composite network can realize integration of three functions of absorption, isolation and common-mode rejection, effectively improves the utilization rate of a circuit structure, is simple and compact in structure and easy to integrate, and has the advantages of full-band absorption, full-band isolation, high frequency selectivity, wide common-mode rejection bandwidth and high out-of-band rejection.

Description

Technical Field

[0001] The invention relates to a microwave radio frequency communication device, in particular to a balanced reflectionless filtering power divider. Background Art

[0002] Balanced microwave RF circuits have the advantages of strong anti-electromagnetic interference ability and environmental noise suppression. They can transmit differential signals to meet the needs of high-quality communication in the system and have been rapidly developed. On the other hand, filter devices in the communication system will generate reflection signals in the stopband range, which will affect the working stability of nonlinear sensitive devices in the RF front-end system and reduce the communication quality. The current technical means to solve this problem is to build an absorption circuit in the filter device, dissipate the reflection signal with the help of the resistor in the absorption circuit, and avoid the reflection signal from entering the RF front-end to cause interference. Therefore, the RF circuit with non-reflection characteristics ensures the signal stability of the communication system outside the passband range. If the absorption circuit is introduced into the balanced circuit and a balanced circuit with non-reflection function is constructed, then the device can not only have strong anti-electromagnetic interference ability and environmental noise suppression, but also ensure the stability of the communication system. At the same time, in order to integrate more circuit functions into the limited RF front-end system space and meet the development trend of miniaturization and high integration of wireless communication systems, multifunctional fusion devices are increasingly attracting widespread attention. The above-mentioned balanced circuit with no reflection function is integrated with filtering and power division functions to form a balanced filter power divider with no reflection function, wherein filtering and power division functions are integrated into the filter power divider, isolation and common mode suppression functions are integrated into the absorption circuit, and an absorption-isolation-common mode suppression composite network is constructed. Then the device will simultaneously obtain strong anti-electromagnetic interference capability, environmental noise suppression, direct differential circuit, filtering, power division and absorption functions, and can also meet the needs of miniaturization and high integration.

[0003] At present, the existing balanced filter power divider does not have the function of no reflection, and the existing no reflection filter power divider devices mainly realize the absorption of reflected signals by loading a complementary filter circuit with an absorption resistor in parallel at the input / output end. This multifunctional fusion not only needs to consider the design of the isolation circuit on the basis of the filter power divider, but also needs to take into account the performance of the parallel absorption circuit, which will further increase the complexity and design difficulty of the circuit. In addition, the common mode suppression performance in the balanced circuit is crucial and is an important indicator for measuring circuit performance. There are two main methods for realizing common mode suppression in the existing balanced filter power divider. One is to add a half-wavelength transmission line between the balanced ports and realize common mode suppression by using the principle of phase cancellation. The disadvantage of this method is that the common mode suppression bandwidth is narrow and can only achieve the ideal suppression effect near the center frequency; the other method is to open a slot line in the ground layer and transmit the differential mode signal by magnetic coupling of the slot line, while the common mode signal cannot be transmitted through the slot line, thereby realizing common mode suppression. This method can effectively improve the common mode suppression bandwidth, but the disadvantage is that the slot line structure constructed by the ground layer increases the complexity of the overall design. Therefore, the existing balanced filter power divider not only does not have the reflection-free function, but also has the disadvantages of narrow common mode suppression bandwidth, poor isolation performance, poor frequency selectivity, complex circuit structure, low functional integration, large size, etc. Therefore, it is necessary to propose a new type of high-performance balanced filter power divider, which integrates common mode suppression and isolation functions into a structure with reflection-free function, and takes into account the requirements of miniaturization and high integration while obtaining the advantages of reflection-free filtering, wide common mode suppression bandwidth, good isolation performance, etc. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a balanced reflectionless filtering power divider is proposed, which has the advantages of full-band reflectionless, wide-band common-mode suppression, excellent isolation performance and high frequency selectivity.

[0005] Technical solution: A balanced non-reflective filtering power divider, comprising a first transmission line and a second transmission line, a first three-wire coupled line and a second three-wire coupled line, a first half-wavelength open-circuit branch and a second half-wavelength open-circuit branch, a first half-wavelength transmission line and a second half-wavelength transmission line, an absorption-isolation-common-mode suppression composite network, a balanced input port and two balanced output ports;

[0006] The absorption-isolation-common-mode suppression composite network is composed of two groups of branch strings with the same structure, and each branch string is composed of two quarter-wavelength transmission lines and two resistors in series;

[0007] The left end of the first transmission line is connected to the balanced input port P1+, and the right end is respectively connected to one end of the first branch string of the absorption-isolation-common-mode suppression composite network and the left end of the first coupling line of the first three-wire coupling line; the left end of the second transmission line is connected to the balanced input port P1-, and the right end is respectively connected to the other end of the first branch string of the absorption-isolation-common-mode suppression composite network and the left end of the first coupling line of the second three-wire coupling line;

[0008] The right end of the first coupling line of the first three-wire coupling line is connected to one end of the second branch string of the absorption-isolation-common mode suppression composite network; the left end of the second coupling line of the first three-wire coupling line is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line of the first three-wire coupling line is respectively connected to the balanced output port P2- and the right end of the first half-wavelength transmission line, and the right end of the third coupling line of the first three-wire coupling line is connected to the first half-wavelength open-circuited branch; the right end of the first coupling line of the second three-wire coupling line is connected to the other end of the second branch string of the absorption-isolation-common mode suppression composite network; the left end of the second coupling line of the second three-wire coupling line is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line of the second three-wire coupling line is respectively connected to the balanced output port P3- and the right end of the second half-wavelength transmission line, and the right end of the second three-wire coupling line is connected to the second half-wavelength open-circuited branch; the left end of the first half-wavelength transmission line is connected to the balanced output port P2+, and the left end of the second half-wavelength transmission line is connected to the balanced output port P3+.

[0009] Furthermore, the absorption-isolation-common-mode suppression composite network is composed of two groups of branch strings with the same structure but different parameters, and each branch string is composed of two quarter-wavelength transmission lines and two resistors in series.

[0010] Furthermore, the structure of the balanced reflectionless filtering power divider is vertically symmetrical with respect to the horizontal plane.

[0011] Beneficial effects: The existing balanced filter power divider does not have the function of no reflection, and also has the problems of narrow common-mode suppression bandwidth, complex overall circuit structure, large size, low circuit structure utilization, low integration, narrow isolation signal bandwidth, low isolation, and poor out-of-band suppression. A balanced reflectionless filter power divider of the present invention constructs an absorption-isolation-common-mode suppression composite network that can realize the integration of the three functions of absorption, isolation and common-mode suppression, effectively improves the utilization of the circuit structure, and has a simple and compact structure, easy to integrate, while taking into account the advantages of full-band absorption, full-band isolation, high frequency selectivity, wide common-mode suppression bandwidth, and high out-of-band suppression.

[0012] Specifically, the absorption-isolation-common-mode suppression composite network is composed of two groups of branch strings with the same structure but different parameters, and each branch string is composed of two quarter-wavelength transmission lines and two resistors in series. Among them, the resistance value of the resistor in the first branch string is approximately equal to the standard port impedance of 50 ohms, and the resistance value of the resistor in the second branch string is greater than the resistance value of the resistor in the first branch string. The quarter-wavelength transmission line is used to switch the working state of the resistor connected to it, which enables the resistor to work in the stop band of differential mode excitation and in the pass band of common mode excitation, and finally realizes the integration of the three functions of full-band reflection-free, broadband isolation and common-mode suppression.

[0013] The constructed three-wire coupled line TCL1 / TCL2 and half-wavelength open-circuit branches TL5 / TL6 series structure realizes high-performance filtering function and has excellent characteristics of wide bandwidth, high frequency selectivity and high out-of-band suppression. At the same time, the structure is simple and compact and easy to integrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a circuit schematic diagram of a balanced non-reflective filtering power divider;

[0015] Figure 2 It is a schematic diagram of a differential mode excitation equivalent circuit of a balanced non-reflection filtering power divider;

[0016] Figure 3 It is a schematic diagram of an equivalent circuit in the differential mode excitation passband of a balanced non-reflective filter power divider;

[0017] Figure 4 It is a schematic diagram of an equivalent circuit in the differential mode excitation stop band of a balanced non-reflection filter power divider;

[0018] Figure 5 A schematic diagram of a common-mode equivalent circuit of a balanced non-reflective filtering power divider;

[0019] Figure 6 It is a schematic diagram of an equivalent circuit in the common-mode excitation passband of a balanced non-reflective filter power divider;

[0020] Figure 7 A schematic diagram of the structural dimensions of a three-wire coupling line in a balanced non-reflection filtering power divider;

[0021] Figure 8 The differential mode transmission coefficient S of a balanced non-reflection filter power divider under ADS simulation dd21 &S dd31 And the differential mode input reflection coefficient S dd11 ;

[0022] Fig. 9 The differential mode isolation coefficient S of a balanced non-reflection filter power divider under ADS simulation dd23 and common mode rejection S cc21;

[0023] Fig.10 It is a schematic diagram of the layout structure of a balanced non-reflective filtering power divider;

[0024] Fig.11 A schematic diagram of the layout dimensions of a balanced non-reflective filtering power divider;

[0025] Fig.12 The differential mode transmission coefficient S of a balanced non-reflection filter power divider under CST full-wave simulation is dd21 &S dd31 And the differential mode input reflection coefficient S dd11 ;

[0026] Fig.13 The differential mode isolation coefficient S of a balanced non-reflection filter power divider under CST full-wave simulation dd23 and common mode rejection S cc21 . DETAILED DESCRIPTION

[0027] The present invention will be further explained below in conjunction with the accompanying drawings.

[0028] A balanced non-reflective filter power divider, the circuit structure of which is as follows Figure 1 As shown, it mainly consists of transmission lines TL1 and TL2, three-line coupled lines TCL1 and TCL2, half-wavelength open branches TL5 and TL6, half-wavelength transmission lines TLc1 and TLc2, an absorption-isolation-common mode suppression composite network 101, a balanced input port P1+ / P1- and two balanced output ports P2+ / P2- and P3+ / P3-.

[0029] The left end of the transmission line TL1 is connected to the balanced input port P1+, and the right end is respectively connected to one end of the resistor Re1 in the absorption-isolation-common-mode suppression composite network 101 and the left end of the first coupling line a of the three-wire coupling line TCL1; the left end of the transmission line TL2 is connected to the balanced input port P1-, and the right end is respectively connected to one end of the resistor Re2 in the absorption-isolation-common-mode suppression composite network 101 and the left end of the first coupling line a of the three-wire coupling line TCL2.

[0030] The right end of the first coupling line a of the three-wire coupling line TCL1 is connected to one end of the resistor Re3 in the absorption-isolation-common mode suppression composite network 101; the left end of the second coupling line b of the three-wire coupling line TCL1 is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line c of the three-wire coupling line TCL1 is respectively connected to the balanced output port P2- and the right end of the half-wavelength transmission line TLc1, and the right end of the third coupling line c of the three-wire coupling line TCL1 is connected to the half-wavelength open branch TL5. The right end of the first coupling line a of the three-wire coupling line TCL2 is connected to one end of the resistor Re4 in the absorption-isolation-common mode suppression composite network 101; the left end of the second coupling line b of the three-wire coupling line TCL2 is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line c of the three-wire coupling line TCL2 is respectively connected to the balanced output port P3- and the right end of the half-wavelength transmission line TLc2, and the right end of the three-wire coupling line TCL2 is connected to the half-wavelength open branch TL6. The left end of the half-wavelength transmission line TLc1 is connected to the balanced output port P2+. The left end of the half-wavelength transmission line TLc2 is connected to the balanced output port P3+.

[0031] The absorption-isolation-common mode suppression composite network 101 is composed of transmission lines TL3, TL4 and resistors Re1 to Re4. The upper end of resistor Re1 is respectively connected to the right end of transmission line TL1 and the left end of the first coupling line a of the three-wire coupling line TCL1, and the lower end is connected to the upper end of transmission line TL3, the lower end of transmission line TL3 is connected to the upper end of resistor Re2, and the lower end of resistor Re2 is respectively connected to the right end of transmission line TL2 and the left end of the first coupling line a of the three-wire coupling line TCL2. The upper end of resistor Re3 is connected to the right end of the first coupling line a of the three-wire coupling line TCL1, and the lower end is connected to the upper end of transmission line TL4, the lower end of transmission line TL4 is connected to the upper end of resistor Re4, and the lower end of resistor Re4 is respectively connected to the right end of the first coupling line a of the three-wire coupling line TCL2. The resistance value of resistor Re3 is approximately equal to the standard port impedance of 50 ohms, and the resistance value of resistor Re3 is greater than the resistance value of resistor Re1.

[0032] A balanced non-reflection filter power divider circuit structure is completely symmetrical about the horizontal plane position. Microwave radio frequency signals are fed from the balanced input port P1+ / P1-. When a pair of differential mode signals are fed from the balanced input port P1+ / P1-, the signals are equally divided and transmitted through transmission lines TL1 and TL2, forming a power divider function. After entering the three-wire coupling lines TCL1 and TCL2, the bandpass filtering function is realized. The half-wavelength open-circuit branches TL5 and TL6 provide a pair of transmission zero points on both sides of the passband, thereby improving the frequency selectivity of the filter power divider. At the same time, the differential mode signal passes through the absorption-isolation-common mode suppression composite network 101 to form a non-reflection and isolation function. Finally, one path of the differential mode signal is output from the balanced output port P2- / P3-, and the other path flows through the half-wavelength transmission line TLc1 / TLc2 and is output from the balanced output port P2+ / P3+; and when a pair of common mode signals are fed from the balanced input port P1+ / P1-, the signals are equally transmitted through the transmission lines TL1 and TL2, and after passing through the absorption-isolation-common mode suppression composite network 101, the common mode signal is effectively suppressed, forming a common mode suppression function.

[0033] In terms of working mechanism, the three-wire coupled lines TCL1 and TCL2 provide a bandpass filter response for the filter power divider, and the half-wavelength open-circuit branches TL5 and TL6 introduce a pair of transmission zeros on both sides of the passband to further improve the frequency selectivity and out-of-band suppression performance. Transmission lines TL1 and TL2 are used to form a good impedance match. The role of the half-wavelength transmission lines TLc1 and TLc2 is to build a balanced output port, and the differential mode signal is output as two signals with a phase difference of 180°.

[0034] In order to illustrate that the absorption-isolation-common-mode suppression composite network 101 has absorption, isolation and common-mode suppression functions, the reflectionless filtering power divider of the present invention is analyzed by using the method of differential-mode excitation and common-mode excitation equivalent circuit.

[0035] Figure 1 The following is a schematic diagram of the circuit structure of a balanced non-reflection filter power divider according to the present invention. Figure 1 As shown, the absorption-isolation-common mode suppression composite network 101 includes four resistors, which can effectively suppress the signal crosstalk between the two balanced output ports. Therefore, the absorption-isolation-common mode suppression composite network 101 realizes the isolation function of the full frequency band.

[0036] Figure 2 FIG. 1 is a schematic diagram of a differential mode excitation equivalent circuit of a balanced non-reflection filter power divider of the present invention. Figure 2As shown, under the excitation of the differential mode, the center plane of the circuit symmetrical about the upper and lower parts is equivalent to an electric wall. At this time, the absorption-isolation-common mode suppression composite network 101 is equivalent to the composite network 101-1. Further, in the passband, the lower ends of the quarter-wavelength transmission lines TL3 and TL4 are equivalent to a short-circuit state, and the upper ends are open-circuit state. At this time, the resistors Re1 and Re3 cannot work, and the equivalent circuit is as follows: Figure 3 As shown in the figure, it can be seen that the composite network 101-1 in the passband does not work, indicating that the absorption-isolation-common mode suppression composite network 101 will not affect the filtering and power division of the signal, ensuring the filtering performance such as low loss and passband flatness. In the stopband, the lower ends of the quarter-wavelength transmission lines TL3 and TL4 are equivalent to a short-circuit state, and the upper ends are still equivalent to a short-circuit state. At this time, the resistors Re1 and Re3 will work normally. The equivalent circuit is as follows Figure 4 As shown in the figure, it can be seen that the reflected signal in the filter stop band will flow to the grounding resistors Re1 and Re3 and be dissipated, indicating that the composite network 101-1 can effectively prevent the reflected signal from flowing to the balanced input port and realize the non-reflection function.

[0037] Figure 5 The figure is a schematic diagram of a common-mode excitation equivalent circuit of a compact balanced-balanced reflectionless filter power divider of the present invention. Figure 5 As shown, under the common mode excitation, the center plane of the circuit symmetrical about the upper and lower sides is equivalent to a magnetic wall. At this time, the absorption-isolation-common mode suppression composite network 101 is equivalent to the composite network 101-2. Further, in the passband, the lower ends of the quarter-wavelength transmission lines TL3 and TL4 are equivalent to an open circuit state, and the upper ends are short-circuited. At this time, the resistors Re1 and Re3 work normally, and the equivalent circuit is as follows: Figure 6 As shown in the figure, it can be seen that the common-mode signal in the passband will flow to the grounding resistors Re1 and Re3 and be dissipated, indicating that the composite network 101-2 can effectively suppress the transmission of the common-mode signal in the passband. The common-mode signal outside the passband is in the filter stopband range, so it cannot be transmitted. Therefore, the present invention realizes the common-mode suppression function of the full frequency band.

[0038] Compared with the existing balanced filter power divider, the present invention constructs an absorption-isolation-common mode suppression composite network 101, realizes the integration of the three functions of absorption, isolation and common mode suppression, effectively improves the utilization rate of the circuit structure, and has a simple and compact structure, easy to integrate, and takes into account the advantages of full-band absorption, full-band isolation, high frequency selectivity, high out-of-band suppression, etc. At the same time, a three-wire coupled line TCL1 / TCL2 and a half-wavelength open branch TL5 / TL6 series structure are constructed, providing a high-performance filtering function, with a simple and compact structure and easy integration. The overall design effectively simplifies the design and reduces the complexity.

[0039] In the absorption-isolation-common-mode suppression composite network 101, the parameter confirmation method of the branch string is as follows: 1. First set the center frequency f, optimize the parameters to determine the filtering structure, including TLC1, TL1, and TCL1, to ensure that the out-of-band suppression is >30dB, good frequency selection performance, and a transmission zero is formed on both sides outside the passband; 2. During differential mode excitation, the fundamental mode must be equivalent to 1 / 4 wavelength grounding, which is directly equivalent to an open circuit. The composite network has no effect on the band, and resistors R1 and R2 have no effect. Therefore, TL3 and TL4 must be 180°; during common-mode excitation, the composite network is equivalent to resistors R1 and R2 grounding. In order to suppress common-mode signals, the impedance of the two parallel branches R1 grounding and R2 grounding must match the input impedance to allow the common-mode signal to flow into the R1 and R2 branches for absorption. Therefore, R1 should be close to 50 ohms, and R2 is obtained based on circuit optimization; 3. The final parameter value is established through further optimization.

[0040] In order to better illustrate the technical effect of the present invention, the present invention designs a balanced non-reflective filter power divider with a center frequency of 2 GHz, and performs ADS simulation verification. The structural parameters in the circuit are Z1 = 47Ω, Z2 = 45.4Ω, Z3 = 45.9Ω, Z4 = 150Ω, Z C =45Ω, R1=62.3Ω, R2=190.8Ω, and the port impedance is 50Ω. The dimensions of the three-wire coupled lines TCL1 and TCL2 in the circuit are as follows: Figure 7 As shown, wherein L1=24.1mm, W1=1.3mm, W2=0.3mm, S=0.81mm, r=0.3mm, d=0.3mm.

[0041] Figure 8 is the differential mode transmission coefficient S obtained by ADS simulation software in this embodiment dd21 &S dd31 And the differential mode input reflection coefficient S dd11 As can be seen from the figure, the center frequency of the filter power divider is 2GHz, the differential mode 3-dB relative bandwidth is 31% (corresponding to the frequency band of 1.69-2.31GHz), and the four transmission zero points are located at 0.4GHz, 1.3GHz, 2.75GHz, and 3.85GHz, respectively, showing good out-of-band suppression and frequency selectivity. Differential mode input end reflection coefficient S dd11 In the 0-5GHz frequency band, it can be less than -10.8dB, with good full-band absorption performance. Two transmission poles are generated in the passband, located at 1.66GHz and 2.06GHz respectively, showing good passband flatness and matching.

[0042] Fig. 9 is the differential mode isolation coefficient S obtained by ADS simulation software in this embodimentdd23 and common mode rejection S cc21 As can be seen from the figure, the isolation coefficient S of the differential signal dd23 In the 0-5GHz frequency band, the transmission coefficient of the common mode signal is less than -21.5dB, and the full-band isolation performance is good. cc21 In the frequency band of 0-4.6GHz, it can suppress to more than 23dB, and the common mode suppression performance of the whole band is good.

[0043] Fig.10 This is a schematic diagram of the layout structure of a balanced non-reflective filter power divider of the present invention, and its size structure schematic diagram is as follows Fig.11 As shown in the figure, the parameters are optimized by the full-wave simulation software CST. The dielectric substrate is RO4003C, with a dielectric constant of 3.55 and a thickness of 1.524mm. Finally, a balanced non-reflective filter power divider with a center frequency of 2GHz is designed. Its parameters are as follows: The three-wire coupling line part is still Figure 7 Dimensions shown: W1 = 1.96mm, W2 = 0.9mm, L1 = 23.4mm, S = 0.52mm, r = 0.3mm, d = 0.3mm. Remaining parts: Lp = 22.4mm, Wp = 3.3mm, L3 = 19.2mm, W3 = 3.9mm, L4 = 44.8mm, W4 = 4.4mm, L5 = 45.6mm, W5 = 4.1mm, L6 = 51.2mm, W6 = 0.13mm, Lc = 51.2mm, Wc = 3.7mm, R1 = 43.3Ω, R2 = 94.5Ω.

[0044] Fig.12 is the differential mode transmission coefficient S obtained by CST full-wave simulation software in this embodiment dd21 &S dd31 And the differential mode input reflection coefficient S dd11 As can be seen from the figure, the center frequency of the filter power divider is 2.0GHz, the differential mode 3-dB relative bandwidth is 30% (corresponding to the frequency band of 1.69-2.69GHz), and the six transmission zero points are located at 0GHz, 1.2GHz, 2.5GHz, 3.1GHz, 4.2GHz, and 5GHz, respectively, showing good out-of-band suppression and frequency selectivity. Differential mode input end reflection coefficient S dd11 In the frequency band of 0-5.18GHz, it can be less than -10dB, and the full-band absorption performance is good. Two transmission poles are generated in the passband, located at 1.66GHz and 2.06GHz respectively, showing good passband flatness and matching.

[0045] Fig.13 is the differential mode isolation coefficient S obtained by CST full-wave simulation software in this embodiment dd23and common mode rejection S cc21 As can be seen from the figure, the isolation coefficient S of the differential signal dd23 In the 0-5.5GHz frequency band, it can be less than -21.5dB, and the full-band isolation performance is good. The transmission coefficient of the common mode signal S cc21 It can suppress more than 20dB in the frequency band of 0-5.5GHz, and the common mode suppression performance of the whole band is good.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A balanced non-reflective filter power divider, It is characterized in that It comprises a first transmission line (TL1) and a second transmission line (TL2), a first three-line coupled line (TCL1) and a second three-line coupled line (TCL2), a first half-wavelength open-circuit branch (TL5) and a second half-wavelength open-circuit branch (TL6), a first half-wavelength transmission line (TLc1) and a second half-wavelength transmission line (TLc2), an absorption-isolation-common-mode suppression composite network (101), a balanced input port, and two balanced output ports; The absorption-isolation-common-mode suppression composite network (101) is composed of two groups of branch strings with the same structure, and each branch string is composed of two quarter-wavelength transmission lines and two resistors in series; The left end of the first transmission line (TL1) is connected to the balanced input port P1+, and the right end is respectively connected to one end of the first branch string of the absorption-isolation-common mode suppression composite network (101) and the left end of the first coupling line of the first three-line coupling line (TCL1); the left end of the second transmission line (TL2) is connected to the balanced input port P1-, and the right end is respectively connected to the other end of the first branch string of the absorption-isolation-common mode suppression composite network (101) and the left end of the first coupling line of the second three-line coupling line (TCL2); The right end of the first coupling line of the first three-wire coupling line (TCL1) is connected to one end of the second branch string of the absorption-isolation-common mode suppression composite network (101); the left end of the second coupling line of the first three-wire coupling line (TCL1) is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line of the first three-wire coupling line (TCL1) is respectively connected to the balanced output port P2- and the right end of the first half-wavelength transmission line (TLc1), and the right end of the third coupling line of the first three-wire coupling line (TCL1) is connected to the first half-wavelength open branch (TL5); the right end of the first coupling line of the second three-wire coupling line (TCL2) is connected to the absorption-isolation- The other end of the second branch string of the common mode suppression composite network (101) is connected; the left end of the second coupling line of the second three-wire coupling line (TCL2) is open-circuited, and the right end is short-circuited and grounded; the left end of the third coupling line of the second three-wire coupling line (TCL2) is respectively connected to the balanced output port P3- and the right end of the second half-wavelength transmission line (TLc2), and the right end of the second three-wire coupling line (TCL2) is connected to the second half-wavelength open-circuit branch (TL6); the left end of the first half-wavelength transmission line (TLc1) is connected to the balanced output port P2+, and the left end of the second half-wavelength transmission line (TLc2) is connected to the balanced output port P3+.

2. The balanced reflectionless filter power divider according to claim 1, It is characterized in that The absorption-isolation-common-mode suppression composite network (101) is composed of two groups of branch strings with the same structure but different parameters, and each branch string is composed of two quarter-wavelength transmission lines and two resistors connected in series.

3. The balanced reflectionless filter power divider according to claim 1 or 2, It is characterized in that The structure of the balanced non-reflective filtering power divider is vertically symmetrical with respect to the horizontal plane.

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