Balanced non-magnetic non-reciprocal band-pass filter with differential-mode and common-mode reflection-free characteristics

Abstract

The invention discloses a balanced non-magnetic non-reciprocal band-pass filter with differential mode and common mode reflection-free characteristics. Comprising a balanced differential input port A, a balanced differential output port B, four quarter-wavelength parallel coupling lines, four absorption resistors, four half-wavelength open-circuit transmission lines, two half-wavelength resonant microstrip lines, two time modulation resonant microstrip lines and four varactors. Two quarter-wavelength feed microstrip lines; and two power supplies. The filter not only can effectively suppress common-mode noise, but also can realize a non-reflection absorption function of a common-mode signal, and is beneficial to improving the electromagnetic compatibility characteristic of a balanced radio frequency circuit. Meanwhile, the filter has the functions of non-reflection absorption and reverse isolation of differential mode signals, and signal integrity can be improved.

Description

Technical Field

[0001] This invention relates to a balanced bandpass filter, specifically a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics. Background Technology

[0002] In modern wireless communication systems, microwave attenuators are frequently used in various applications requiring power level adjustment to control the transmitted power, such as controlling the input and output levels of amplifiers and controlling branch attenuation. Especially in microwave power measurement systems, microwave attenuators are needed to attenuate the signal power to a level within the measurable range of the measurement system before accurate measurement and analysis. To adapt to increasingly complex system environments, simple structure, integrated functions, and convenient control have become important development directions for microwave attenuators. Therefore, the combined design of attenuators and filters, utilizing filter circuit topologies to achieve integrated filter responses, has broad application prospects.

[0003] With the increasing amount of information transmitted in mobile communication systems, in addition to requiring communication equipment to have higher data transmission capabilities, stricter requirements are also placed on the signal margin. Traditional single-port input / output circuits transmit and process unbalanced signals. When noise enters the communication receiving system, it can easily cause logical misjudgments, thereby reducing the system's receiving sensitivity. Compared to unbalanced single-ended input / output circuits, balanced circuits can efficiently suppress environmental noise and noise generated by internal active components, thus exhibiting superior electromagnetic compatibility characteristics. Conventional balanced circuits achieve suppression by reflecting unwanted common-mode noise back to the signal source. In nonlinear systems, the common-mode noise reflected back to the signal source mixes with the existing signal, generating numerous interference signals that significantly impact system performance. The introduction of common-mode non-reflection balanced circuits can effectively absorb common-mode noise through resistors and dissipate it as heat, reducing the return energy of common-mode noise and thus improving the overall system performance.

[0004] However, existing common-mode reflection-free balanced circuits still suffer from problems such as complex circuit structure, large size, and narrow common-mode reflection-free bandwidth. Furthermore, research on balanced filter attenuators is extremely scarce. Therefore, researching a balanced filter attenuator with frequency selectivity in the differential mode and reflection-free characteristics in the common mode is of great significance. In view of this, it is indeed necessary to propose a balanced filter attenuator with full-band common-mode reflection-free characteristics. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention discloses a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics, comprising: a balanced differential input port A, a balanced differential output port B, four quarter-wavelength parallel coupling lines, four absorption resistors, four half-wavelength open-circuit transmission lines, two three-half-wavelength resonant microstrip lines, two time-modulated resonant microstrip lines, four varactor diodes, two quarter-wavelength fed microstrip lines, and two power supplies;

[0006] The balanced differential input port A includes input port A+ and input port A-;

[0007] The balanced differential output port B includes output port B+ and output port B-;

[0008] The four quarter-wavelength parallel coupling lines include a first parallel coupling line, a second parallel coupling line, a third parallel coupling line, and a fourth parallel coupling line; wherein the A port of the first parallel coupling line is open, the B port of the first parallel coupling line is connected to the connection between the input port A+ and the first open-circuit transmission line, the C port of the first parallel coupling line is connected to the C port of the third parallel coupling line, and the D port of the first parallel coupling line is connected to the first absorption resistor; the A port of the second parallel coupling line is open, the B port of the second parallel coupling line is connected to the connection between the output port B+ and the second open-circuit transmission line, and the C port of the second parallel coupling line is connected to the C port of the fourth parallel coupling line. The first parallel line is connected to the second parallel line, with its D port connected to the second absorption resistor; the third parallel line has its A port open, its B port connected to the connection between the input port A- and the third open transmission line, its C port connected to the C port of the first parallel line, and its D port connected to the third absorption resistor; the fourth parallel line has its A port open, its B port connected to the connection between the output port B- and the fourth open transmission line, its C port connected to the C port of the second parallel line, and its D port connected to the fourth absorption resistor.

[0009] The four absorption resistors include a first absorption resistor, a second absorption resistor, a third absorption resistor, and a fourth absorption resistor; wherein one end of the first absorption resistor is connected to the D port of the first parallel coupling line and the other end is grounded; one end of the second absorption resistor is connected to the D port of the second parallel coupling line and the other end is grounded; one end of the third absorption resistor is connected to the D port of the third parallel coupling line and the other end is grounded; one end of the fourth absorption resistor is connected to the D port of the fourth parallel coupling line and the other end is grounded.

[0010] The four half-wavelength open-circuit transmission lines include a first open-circuit transmission line, a second open-circuit transmission line, a third open-circuit transmission line, and a fourth open-circuit transmission line; wherein the first open-circuit transmission line includes a first microstrip transmission line and a second microstrip transmission line; the second open-circuit transmission line includes a third microstrip transmission line and a fourth microstrip transmission line; the third open-circuit transmission line includes a fifth microstrip transmission line and a sixth microstrip transmission line; the fourth open-circuit transmission line includes a seventh microstrip transmission line and an eighth microstrip transmission line; one end of the first microstrip transmission line is connected to the connection between the first parallel coupling line and the input port A+, and the other end is connected to the second microstrip transmission line; one end of the second microstrip transmission line is connected to the first microstrip transmission line, and the other end is open-circuit. The third microstrip transmission line is connected at one end to the connection between the second parallel coupling line and the output port B+, and at the other end to the fourth microstrip transmission line; one end of the fourth microstrip transmission line is connected to the third microstrip transmission line, and the other end is open; one end of the fifth microstrip transmission line is connected to the connection between the third parallel coupling line and the input port A-, and at the other end to the sixth microstrip transmission line; one end of the sixth microstrip transmission line is connected to the fifth microstrip transmission line, and the other end is open; one end of the seventh microstrip transmission line is connected to the connection between the fourth parallel coupling line and the output port B-, and at the other end to the eighth microstrip transmission line; one end of the eighth microstrip transmission line is connected to the seventh microstrip transmission line, and the other end is open;

[0011] The two three-half wavelength resonant microstrip lines include a first resonant microstrip line and a second resonant microstrip line; wherein the first resonant microstrip line includes a first coupled resonant microstrip line, a second coupled resonant microstrip line, a third coupled resonant microstrip line, a fourth coupled resonator microstrip line, and a fifth coupled resonant microstrip line; the second resonant microstrip line includes a sixth coupled resonant microstrip line, a seventh coupled resonant microstrip line, an eighth coupled resonant microstrip line, a ninth coupled resonator microstrip line, and a tenth coupled resonant microstrip line; one end of the first coupled resonant microstrip line is connected to the second coupled resonant microstrip line, and the other end is open-circuited; one end of the second coupled resonant microstrip line is connected to the first coupled resonant microstrip line, and the other end is connected to the third coupled resonant microstrip line; one end of the third coupled resonant microstrip line is connected to the second coupled resonant microstrip line, and the other end is connected to the fourth coupled resonant microstrip line. The fourth coupled resonant microstrip line has one end connected to the third coupled resonant microstrip line and the other end connected to the fifth coupled resonant microstrip line; the fifth coupled resonant microstrip line has one end connected to the fourth coupled resonant microstrip line and the other end open; the sixth coupled resonant microstrip line has one end connected to the seventh coupled resonant microstrip line and the other end open; the seventh coupled resonant microstrip line has one end connected to the sixth coupled resonant microstrip line and the other end connected to the eighth coupled resonant microstrip line; the eighth coupled resonant microstrip line has one end connected to the seventh coupled resonant microstrip line and the other end connected to the ninth coupled resonant microstrip line; the ninth coupled resonant microstrip line has one end connected to the eighth coupled resonant microstrip line and the other end connected to the tenth coupled resonant microstrip line; the tenth coupled resonant microstrip line has one end connected to the ninth coupled resonant microstrip line and the other end open.

[0012] The two time-modulated resonant microstrip lines include a first time-modulated resonant microstrip line and a second time-modulated resonant microstrip line; wherein the first time-modulated resonant microstrip line includes a first time-modulated coupling resonant microstrip line, a second time-modulated coupling resonant microstrip line, a third time-modulated coupling resonant microstrip line, a fourth time-modulated coupling resonant microstrip line, a fifth time-modulated coupling resonant microstrip line, and a sixth time-modulated coupling resonant microstrip line; the second time-modulated resonant microstrip line includes a seventh time-modulated coupling resonant microstrip line, an eighth time-modulated coupling resonant microstrip line, a ninth time-modulated coupling resonant microstrip line, a tenth time-modulated coupling resonant microstrip line, and an eleventh time-modulated coupling resonant microstrip line. The system includes a first time-modulated coupled resonant microstrip line and a twelfth time-modulated coupled resonant microstrip line; one end of the first time-modulated coupled resonant microstrip line is connected to the anode of the first varactor diode, and the other end is grounded; one end of the second time-modulated coupled resonant microstrip line is connected to the cathode of the first varactor diode, and the other end is connected to the third time-modulated coupled resonant microstrip line; one end of the third time-modulated coupled resonant microstrip line is connected to the second time-modulated coupled resonant microstrip line, and the other end is connected to the connection point between the fourth time-modulated coupled resonant microstrip line and the first feed microstrip line; one end of the fourth time-modulated coupled resonant microstrip line is connected to the fifth time-modulated coupled resonant microstrip line, and the other end is connected to... The connection point of the third time-modulated coupled resonant microstrip line and the first feed microstrip line; one end of the fifth time-modulated coupled resonant microstrip line is connected to the fourth time-modulated coupled resonant microstrip line, and the other end is connected to the cathode of the second varactor diode; one end of the sixth time-modulated coupled resonant microstrip line is connected to the anode of the second varactor diode, and the other end is grounded; one end of the seventh time-modulated coupled resonant microstrip line is connected to the anode of the third varactor diode, and the other end is grounded; one end of the eighth time-modulated coupled resonant microstrip line is connected to the cathode of the third varactor diode, and the other end is connected to the ninth time-modulated coupled resonant microstrip line; the ninth time-modulated coupled... One end of the combined resonant microstrip line is connected to the eighth time-modulation coupled resonant microstrip line, and the other end is connected to the connection point between the tenth time-modulation coupled resonant microstrip line and the second feed microstrip line; one end of the tenth time-modulation coupled resonant microstrip line is connected to the eleventh time-modulation coupled resonant microstrip line, and the other end is connected to the connection point between the ninth time-modulation coupled resonant microstrip line and the second feed microstrip line; one end of the eleventh time-modulation coupled resonant microstrip line is connected to the tenth time-modulation coupled resonant microstrip line, and the other end is connected to the cathode of the fourth varactor diode; one end of the twelfth time-modulation coupled resonant microstrip line is connected to the anode of the fourth varactor diode, and the other end is grounded;

[0013] The four varactor diodes include a first varactor diode, a second varactor diode, a third varactor diode, and a fourth varactor diode; wherein the anode of the first varactor diode is connected to a first time-modulated coupled resonant microstrip line, and the cathode of the other end is connected to a second time-modulated coupled resonant microstrip line; the anode of the second varactor diode is connected to a sixth time-modulated coupled resonant microstrip line, and the cathode of the other end is connected to a fifth time-modulated coupled resonant microstrip line; the anode of the third varactor diode is connected to a seventh time-modulated coupled resonant microstrip line, and the cathode of the other end is connected to an eighth time-modulated coupled resonant microstrip line; the anode of the fourth varactor diode is connected to a twelfth time-modulated coupled resonant microstrip line, and the cathode of the other end is connected to an eleventh time-modulated coupled resonant microstrip line.

[0014] The two quarter-wavelength fed microstrip lines include a first fed microstrip line and a second fed microstrip line; wherein one end of the first fed microstrip line is connected to the connection point of the third time-modulated coupled resonant microstrip line and the fourth time-modulated coupled resonant microstrip line, and the other end is connected to the first power supply; one end of the second fed microstrip line is connected to the connection point of the ninth time-modulated coupled resonant microstrip line and the tenth time-modulated coupled resonant microstrip line, and the other end is connected to the second power supply;

[0015] The two power supplies include a first power supply and a second power supply; wherein the first power supply is connected to a first feed microstrip line; and the second power supply is connected to a second feed microstrip line.

[0016] The second microstrip transmission line and the second coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the fourth microstrip transmission line and the seventh coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the sixth microstrip transmission line and the fourth coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the eighth microstrip transmission line and the ninth coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0017] The first coupled resonant microstrip line and the third time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the sixth coupled resonant microstrip line and the ninth time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the fifth coupled resonant microstrip line and the fourth time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the tenth coupled resonant microstrip line and the tenth time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0018] The second time-modulated coupled resonant microstrip line and the eighth time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect; the fifth time-modulated coupled resonant microstrip line and the eleventh time-modulated coupled resonant microstrip line are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0019] By adjusting the DC voltage V output from the first power supply dc AC voltage amplitude V ac Frequency f m Initial phase DC voltage V output from the second power supply dc AC voltage amplitude V ac Frequency f m Initial phase By completing time modulation, controlling the transmission of the forward differential signal, and simultaneously cutting off the reverse differential signal, the non-reciprocity of a balanced tapeless pass-through filter with differential and common-mode non-reflection characteristics is achieved.

[0020] The first and second power supplies only output DC voltage V dc At this time, the filter is a balanced reciprocal bandpass filter with differential and common-mode non-reflection characteristics.

[0021] By adjusting the odd-mode and even-mode characteristic impedances of the first parallel coupling line, the second parallel coupling line, the third parallel coupling line, the fourth parallel coupling line, the resistance values ​​of the first absorption resistor, the second absorption resistor, the third absorption resistor, and the fourth absorption resistor, the differential-mode and common-mode reflection-free absorption characteristics of the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics can be adjusted.

[0022] The coupling between the second microstrip transmission line and the second coupled resonant microstrip line, the coupling between the fourth microstrip transmission line and the seventh coupled resonant microstrip line, the coupling between the sixth microstrip transmission line and the fourth coupled resonant microstrip line, and the coupling between the eighth microstrip transmission line and the ninth coupled resonant microstrip line exhibit a full-resistance response under common-mode signal excitation, thus achieving common-mode rejection characteristics.

[0023] By adjusting the characteristic impedance of four half-wavelength open-circuit transmission lines, the distance between the second microstrip transmission line and the second coupled resonant microstrip line, the distance between the fourth microstrip transmission line and the seventh coupled resonant microstrip line, the distance between the sixth microstrip transmission line and the fourth coupled resonant microstrip line, the distance between the eighth microstrip transmission line and the ninth coupled resonant microstrip line, the distance between the first coupled resonant microstrip line and the third time-modulated coupled resonant microstrip line, the distance between the sixth coupled resonant microstrip line and the ninth time-modulated coupled resonant microstrip line, the distance between the fifth coupled resonant microstrip line and the fourth time-modulated coupled resonant microstrip line, the distance between the tenth coupled resonant microstrip line and the tenth time-modulated coupled resonant microstrip line, the distance between the second time-modulated coupled resonant microstrip line and the eighth time-modulated coupled resonant microstrip line, and the distance between the fifth time-modulated coupled resonant microstrip line and the eleventh time-modulated coupled resonant microstrip line, the passband bandwidth and frequency selectivity of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics can be adjusted.

[0024] To improve the anti-interference capability of balanced non-reciprocal bandpass filters and extend their functionality to include differential-mode and common-mode anti-reflection characteristics, this invention provides a balanced non-magnetic non-reciprocal bandpass filter with both differential-mode and common-mode anti-reflection features. This balanced non-magnetic non-reciprocal filter is designed and manufactured using microstrip lines and can be integrated with other circuits on a single PCB board. Good differential-mode and common-mode anti-reflection characteristics are achieved simultaneously by adding quarter-wavelength parallel coupling lines and absorption resistors at the balanced input and output ports. The differential-mode and common-mode anti-reflection characteristics can be optimized by adjusting the characteristic impedance and coupling degree of the quarter-wavelength parallel coupling lines and the resistance value of the absorption resistors. Excellent common-mode rejection is achieved by utilizing the different circuit equivalence relationships of the circuit's horizontal symmetry plane during differential and common-mode signal transmission. The common-mode rejection is independent of the design of the time-modulated resonator section; similarly, the absorption of common-mode noise is unaffected by the DC voltage in the power supply and the selection of modulation signal parameters. The overall circuit design exhibits strong anti-interference capability, ease of integration, and strong electromagnetic compatibility, and is expected to further improve the overall performance of balanced RF circuits. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics according to the present invention.

[0027] Figure 2 This is a differential-mode S-parameter amplitude curve of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics in the absence of time modulation.

[0028] Figure 3 This invention relates to a balanced non-magnetic, non-reciprocal bandpass filter with differential and common-mode reflection-free characteristics, in a time-modulated state, where the differential mode |S ddBA |and|S ddAB |Graph;

[0029] Figure 4 This invention relates to a balanced non-magnetic, non-reciprocal bandpass filter with differential and common-mode reflection-free characteristics, in a time-modulated state, where the differential mode |S ddAA |Graph;

[0030] Figure 5 This is a common-mode S-parameter amplitude curve of a balanced non-magnetic non-reciprocal bandpass filter with differential and common-mode non-reflection characteristics under time modulation state according to the present invention. Detailed Implementation

[0031] To make the technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0032] like Figure 1 The present invention relates to a balanced non-magnetic non-reciprocal bandpass filter with differential and common-mode non-reflection characteristics, comprising: a balanced differential input port A, a balanced differential output port B, four quarter-wavelength parallel coupling lines, four absorption resistors, four half-wavelength open-circuit transmission lines, two three-half-wavelength resonant microstrip lines, two time-modulated resonant microstrip lines, four varactor diodes, two quarter-wavelength fed microstrip lines, and two power supplies.

[0033] The balanced differential input port A includes input port A+1 and input port A-3;

[0034] The balanced differential output port B includes output port B+2 and output port B-4;

[0035] The four quarter-wavelength parallel coupling lines include a first parallel coupling line 5, a second parallel coupling line 6, a third parallel coupling line 7, and a fourth parallel coupling line 8; wherein the first parallel coupling line 5 has an open A port 1a, a B port 1b connected to the connection between the input port A+1 and the first open-circuit transmission line 13, a C port 1c connected to the C port 3c of the third parallel coupling line 7, and a D port 1d connected to the first absorption resistor 9; the second parallel coupling line 6 has an open A port 2a, a B port 2b connected to the connection between the output port B+2 and the second open-circuit transmission line 14, and a C port 2c connected to the C port 4c of the fourth parallel coupling line 8. The second parallel coupling line 6 has its D port 2d connected to the second absorption resistor 10; the third parallel coupling line 7 has its A port 3a open, its B port 3b connected to the connection between the input port A-3 and the third open transmission line 15, its C port 3c connected to the C port 1c of the first parallel coupling line 5, and its D port 3d connected to the third absorption resistor 11; the fourth parallel coupling line 8 has its A port 4a open, its B port 4b connected to the connection between the output port B-4 and the fourth open transmission line 16, its C port 4c connected to the C port 2c of the second parallel coupling line 6, and its D port 4d connected to the fourth absorption resistor 12.

[0036] The four absorption resistors include a first absorption resistor 9, a second absorption resistor 10, a third absorption resistor 11, and a fourth absorption resistor 12; wherein one end of the first absorption resistor 9 is connected to port 1d of the first parallel coupling line 5, and the other end is grounded; one end of the second absorption resistor 10 is connected to port 2d of the second parallel coupling line 6, and the other end is grounded; one end of the third absorption resistor 11 is connected to port 3d of the third parallel coupling line 7, and the other end is grounded; one end of the fourth absorption resistor 12 is connected to port 4d of the fourth parallel coupling line 12, and the other end is grounded.

[0037] The four half-wavelength open-circuit transmission lines include a first open-circuit transmission line 13, a second open-circuit transmission line 14, a third open-circuit transmission line 15, and a fourth open-circuit transmission line 16. The first open-circuit transmission line 13 includes a first microstrip transmission line 131 and a second microstrip transmission line 132. The second open-circuit transmission line 14 includes a third microstrip transmission line 141 and a fourth microstrip transmission line 142. The third open-circuit transmission line 15 includes a fifth microstrip transmission line 151 and a sixth microstrip transmission line 152. The fourth open-circuit transmission line 16 includes a seventh microstrip transmission line 161 and an eighth microstrip transmission line 162. One end of the first microstrip transmission line 131 is connected to the connection point between the first parallel coupling line 5 and the input port A+1, and the other end is connected to the second microstrip transmission line 132. One end of the second microstrip transmission line 132 is connected to the first microstrip transmission line 131. One end of the third microstrip transmission line 141 is connected to the connection between the second parallel coupling line 6 and the output port B+2, and the other end is connected to the fourth microstrip transmission line 142; one end of the fourth microstrip transmission line 142 is connected to the third microstrip transmission line 141, and the other end is open; one end of the fifth microstrip transmission line 151 is connected to the connection between the third parallel coupling line 7 and the input port A-3, and the other end is connected to the sixth microstrip transmission line 152; one end of the sixth microstrip transmission line 152 is connected to the fifth microstrip transmission line 151, and the other end is open; one end of the seventh microstrip transmission line 161 is connected to the connection between the fourth parallel coupling line 8 and the output port B-4, and the other end is connected to the eighth microstrip transmission line 162; one end of the eighth microstrip transmission line 162 is connected to the seventh microstrip transmission line 161, and the other end is open;

[0038] The two three-half wavelength resonant microstrip lines include a first resonant microstrip line 17 and a second resonant microstrip line 18; wherein the first resonant microstrip line 17 includes a first coupled resonant microstrip line 171, a second coupled resonant microstrip line 172, a third coupled resonant microstrip line 173, a fourth coupled resonator microstrip line 174, and a fifth coupled resonant microstrip line 175; the second resonant microstrip line 18 includes a sixth coupled resonant microstrip line 181, a seventh coupled resonant microstrip line 182, and an eighth coupled resonant microstrip line 183. Ninth coupled resonator microstrip line 184 and tenth coupled resonator microstrip line 185; one end of the first coupled resonator microstrip line 171 is connected to the second coupled resonator microstrip line 172, and the other end is open-circuited; one end of the second coupled resonator microstrip line 172 is connected to the first coupled resonator microstrip line 171, and the other end is connected to the third coupled resonator microstrip line 173; one end of the third coupled resonator microstrip line 173 is connected to the second coupled resonator microstrip line 172, and the other end is connected to the fourth coupled resonator microstrip line 175. 4-phase connection; one end of the fourth coupled resonant microstrip line 174 is connected to the third coupled resonant microstrip line 173, and the other end is connected to the fifth coupled resonant microstrip line 175; one end of the fifth coupled resonant microstrip line 175 is connected to the fourth coupled resonant microstrip line 174, and the other end is open-circuited; one end of the sixth coupled resonant microstrip line 181 is connected to the seventh coupled resonant microstrip line 182, and the other end is open-circuited; one end of the seventh coupled resonant microstrip line 182 is connected to the sixth coupled resonant microstrip line 181. One end of the line is connected to the seventh coupled resonant microstrip line 182, and the other end is connected to the ninth coupled resonant microstrip line 184; one end of the ninth coupled resonant microstrip line 184 is connected to the eighth coupled resonant microstrip line 183, and the other end is connected to the tenth coupled resonant microstrip line 185; one end of the tenth coupled resonant microstrip line 185 is connected to the ninth coupled resonant microstrip line 184, and the other end is open-circuited.

[0039] The two time-modulated resonant microstrip lines include a first time-modulated resonant microstrip line 19 and a second time-modulated resonant microstrip line 20; wherein the first time-modulated resonant microstrip line 19 includes a first time-modulated coupled resonant microstrip line 191, a second time-modulated coupled resonant microstrip line 192, a third time-modulated coupled resonant microstrip line 193, a fourth time-modulated coupled resonant microstrip line 194, a fifth time-modulated coupled resonant microstrip line 195, and a sixth time-modulated coupled resonant microstrip line 196; the second time-modulated resonant microstrip line 20 includes a seventh time-modulated coupled resonant microstrip line 201, an eighth time-modulated coupled resonant microstrip line 202, a ninth time-modulated coupled resonant microstrip line 203, and a tenth time-modulated coupled resonant microstrip line 206. Line 204, eleventh time-modulated coupled resonant microstrip line 205, and twelfth time-modulated coupled resonant microstrip line 206; one end of the first time-modulated coupled resonant microstrip line 191 is connected to the anode of the first varactor diode 21, and the other end is grounded; one end of the second time-modulated coupled resonant microstrip line 192 is connected to the cathode of the first varactor diode 21, and the other end is connected to the third time-modulated coupled resonant microstrip line 193; one end of the third time-modulated coupled resonant microstrip line 193 is connected to the second time-modulated coupled resonant microstrip line 192, and the other end is connected to the connection between the fourth time-modulated coupled resonant microstrip line 194 and the first feed microstrip line 25; one end of the fourth time-modulated coupled resonant microstrip line 194... One end of the fifth time-modulation coupled resonant microstrip line 195 is connected to the fifth time-modulation coupled resonant microstrip line 195, and the other end is connected to the connection between the third time-modulation coupled resonant microstrip line 193 and the first feed microstrip line 25; one end of the fifth time-modulation coupled resonant microstrip line 195 is connected to the fourth time-modulation coupled resonant microstrip line 194, and the other end is connected to the cathode of the second varactor diode 22; one end of the sixth time-modulation coupled resonant microstrip line 196 is connected to the anode of the second varactor diode 22, and the other end is grounded; one end of the seventh time-modulation coupled resonant microstrip line 201 is connected to the anode of the third varactor diode 23, and the other end is grounded; one end of the eighth time-modulation coupled resonant microstrip line 202 is connected to the cathode of the third varactor diode 23. One end is connected to the ninth time-modulated coupled resonant microstrip line 203; one end of the ninth time-modulated coupled resonant microstrip line 203 is connected to the eighth time-modulated coupled resonant microstrip line 202, and the other end is connected to the connection between the tenth time-modulated coupled resonant microstrip line 204 and the second feed microstrip line 26; one end of the tenth time-modulated coupled resonant microstrip line 204 is connected to the eleventh time-modulated coupled resonant microstrip line 205, and the other end is connected to the connection between the ninth time-modulated coupled resonant microstrip line 203 and the second feed microstrip line 26; one end of the eleventh time-modulated coupled resonant microstrip line 205 is connected to the tenth time-modulated coupled resonant microstrip line 204, and the other end is connected to the cathode of the fourth varactor diode 24;One end of the twelfth time-modulated coupled resonant microstrip line 206 is connected to the anode of the fourth varactor diode 22, and the other end is grounded;

[0040] The four varactor diodes include a first varactor diode 21, a second varactor diode 22, a third varactor diode 23, and a fourth varactor diode 24; wherein the anode of the first varactor diode 21 is connected to the first time-modulated coupled resonant microstrip line 191, and the cathode of the other end is connected to the second time-modulated coupled resonant microstrip line 192; the anode of the second varactor diode 22 is connected to the sixth time-modulated coupled resonant microstrip line 196, and the cathode of the other end is connected to the fifth time-modulated coupled resonant microstrip line 195; the anode of the third varactor diode 23 is connected to the seventh time-modulated coupled resonant microstrip line 201, and the cathode of the other end is connected to the eighth time-modulated coupled resonant microstrip line 202; the anode of the fourth varactor diode 24 is connected to the twelfth time-modulated coupled resonant microstrip line 206, and the cathode of the other end is connected to the eleventh time-modulated coupled resonant microstrip line 205;

[0041] The two quarter-wavelength fed microstrip lines include a first fed microstrip line 25 and a second fed microstrip line 26; wherein one end of the first fed microstrip line 25 is connected to the connection between the third time-modulated coupled resonant microstrip line 193 and the fourth time-modulated coupled resonant microstrip line 194, and the other end is connected to the first power supply 27; one end of the second fed microstrip line 26 is connected to the connection between the ninth time-modulated coupled resonant microstrip line 203 and the tenth time-modulated coupled resonant microstrip line 204, and the other end is connected to the second power supply 28;

[0042] The two power supplies include a first power supply 27 and a second power supply 28; wherein the first power supply 27 is connected to the first feed microstrip line 25; and the second power supply 28 is connected to the second feed microstrip line 26.

[0043] The second microstrip transmission line 132 and the second coupled resonant microstrip line 172 are both quarter-wavelength, parallel to each other, and have a coupling effect; the fourth microstrip transmission line 142 and the seventh coupled resonant microstrip line 182 are both quarter-wavelength, parallel to each other, and have a coupling effect; the sixth microstrip transmission line 152 and the fourth coupled resonant microstrip line 174 are both quarter-wavelength, parallel to each other, and have a coupling effect; the eighth microstrip transmission line 162 and the ninth coupled resonant microstrip line 184 are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0044] The first coupled resonant microstrip line 171 and the third time-modulated coupled resonant microstrip line 193 are both quarter-wavelength, parallel to each other, and have a coupling effect; the sixth coupled resonant microstrip line 181 and the ninth time-modulated coupled resonant microstrip line 203 are both quarter-wavelength, parallel to each other, and have a coupling effect; the fifth coupled resonant microstrip line 175 and the fourth time-modulated coupled resonant microstrip line 194 are both quarter-wavelength, parallel to each other, and have a coupling effect; the tenth coupled resonant microstrip line 185 and the tenth time-modulated coupled resonant microstrip line 204 are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0045] The second time-modulated coupled resonant microstrip line 192 and the eighth time-modulated coupled resonant microstrip line 202 are both quarter-wavelength, parallel to each other, and have a coupling effect; the fifth time-modulated coupled resonant microstrip line 195 and the eleventh time-modulated coupled resonant microstrip line 205 are both quarter-wavelength, parallel to each other, and have a coupling effect.

[0046] Furthermore, by adjusting the DC voltage V output by the first power supply 27 dc AC voltage amplitude V ac Frequency f m Initial phase The DC voltage V output by the second power supply 28 dc AC voltage amplitude V ac Frequency f m Initial phase By completing time modulation, controlling the transmission of the forward differential signal, and simultaneously cutting off the reverse differential signal, the non-reciprocity of a balanced tapeless pass-through filter with differential and common-mode non-reflection characteristics is achieved.

[0047] Furthermore, the first power supply 27 and the second power supply 28 only output DC voltage V. dc At this time, the filter is a balanced reciprocal bandpass filter with differential and common-mode non-reflection characteristics.

[0048] Furthermore, by adjusting the odd-mode and even-mode characteristic impedances of the first parallel coupling line 5, the second parallel coupling line 6, the third parallel coupling line 7, the fourth parallel coupling line 8, the resistance values ​​of the first absorption resistor 9, the second absorption resistor 10, the third absorption resistor 11, and the fourth absorption resistor 12, the differential-mode and common-mode reflection-free absorption characteristics of the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics can be adjusted.

[0049] Furthermore, the coupling between the second microstrip transmission line 132 and the second coupled resonant microstrip line 172, the coupling between the fourth microstrip transmission line 142 and the seventh coupled resonant microstrip line 182, the coupling between the sixth microstrip transmission line 152 and the fourth coupled resonant microstrip line 174, and the coupling between the eighth microstrip transmission line 162 and the ninth coupled resonant microstrip line 184 exhibit a full-resistance response under common-mode signal excitation, thereby achieving common-mode suppression characteristics.

[0050] Furthermore, by adjusting the characteristic impedance of the four half-wavelength open-circuit transmission lines, the distance between the second microstrip transmission line 132 and the second coupled resonant microstrip line 172, the distance between the fourth microstrip transmission line 142 and the seventh coupled resonant microstrip line 182, the distance between the sixth microstrip transmission line 152 and the fourth coupled resonant microstrip line 174, the distance between the eighth microstrip transmission line 162 and the ninth coupled resonant microstrip line 184, the distance between the first coupled resonant microstrip line 171 and the third time-modulated coupled resonant microstrip line 193, and the distance between the sixth coupled resonant microstrip line 181 and the ninth time-modulated coupled resonant microstrip line 193, the system can achieve the desired effect. The distances between microstrip line 203, the fifth coupled resonant microstrip line 175 and the fourth time-modulated coupled resonant microstrip line 194, the tenth coupled resonant microstrip line 185 and the tenth time-modulated coupled resonant microstrip line 204, the second time-modulated coupled resonant microstrip line 192 and the eighth time-modulated coupled resonant microstrip line 202, and the fifth time-modulated coupled resonant microstrip line 195 and the eleventh time-modulated coupled resonant microstrip line 205 are adjusted to regulate the passband bandwidth and frequency selectivity of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics.

[0051] Specific example: This example illustrates a balanced, non-magnetic, non-reciprocal bandpass filter with both differential-mode and common-mode reflection-free characteristics. For example... Figure 2 As shown, the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics described in this invention, when not time-modulated, behaves as a balanced reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics; the filter's passband center frequency is 1.5 GHz, and the minimum differential-mode transmission loss |S| within the passband is... ddBA | is -1.78dB, 3dB relative bandwidth is 7.3%, filter differential mode reflection coefficient |S ddAA The voltage drop is less than -10 dB in the frequency range of 1.04 GHz to 1.99 GHz. For example... Figure 3 As shown, the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics described in this invention behaves as a balanced non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics under time modulation; the minimum differential-mode transmission loss |S| within the filter's forward passband is... ddBA | is -2.82dB; filter reverse transmission coefficient |S ddABThe bandwidth less than -20dB is 31MHz. For example... Figure 4 As shown, the differential-mode reflection coefficient |S_s of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics described in this invention, under time modulation, at the filter passband center frequency of 1.5 GHz, is... ddAA | is -20.43 dB; differential mode reflection coefficient |S in the frequency range of 1.04 GHz to 1.99 GHz ddAA All are less than -10dB. For example Figure 5 As shown, the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflection characteristics described in this invention, under time modulation state, has a common-mode reflection coefficient |S ccAA The common-mode transmission coefficient is less than -20dB in the frequency range of 1.24GHz to 1.77GHz. ccBA The difference is less than -70dB in the frequency range of 1.13GHz to 1.89GHz. This indicates that the balanced non-magnetic non-reciprocal bandpass filter with differential and common-mode reflection-free characteristics described in this invention has excellent common-mode rejection, differential and common-mode reflection-free characteristics under time modulation, while also having good differential-mode forward filtering transmission and differential-mode reverse isolation characteristics.

[0052] In summary, the balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode anti-reflection characteristics described in this invention is designed and manufactured using an easily integrated microstrip line structure and can be implemented on a single PCB board. Furthermore, this filter not only effectively suppresses common-mode noise but also achieves anti-reflection absorption of common-mode signals, contributing to improved electromagnetic compatibility characteristics of balanced RF circuits. Simultaneously, the filter's anti-reflection absorption of differential-mode signals helps improve signal integrity. Moreover, this balanced non-reciprocal filter combines the reverse isolation characteristics of an isolator with the frequency selectivity of a filter. These characteristics are simultaneously achieved in a single device, aligning with the development trend of multi-functional collaborative design in modern wireless communication circuits, making it highly suitable for application in various balanced microwave systems to improve overall system performance.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics, characterized in that, include: Balanced differential input port A, balanced differential output port B, four quarter-wavelength parallel coupling lines, four absorption resistors, four half-wavelength open-circuit transmission lines, two three-half-wavelength resonant microstrip lines, two time-modulated resonant microstrip lines, four varactor diodes, two quarter-wavelength fed microstrip lines, and two power supplies. The balanced differential input port A includes input port A+(1) and input port A-(3); The balanced differential output port B includes output port B+(2) and output port B-(4); The four quarter-wavelength parallel coupling lines include a first parallel coupling line (5), a second parallel coupling line (6), a third parallel coupling line (7), and a fourth parallel coupling line (8); wherein the A port (1a) of the first parallel coupling line (5) is open, the B port (1b) of the first parallel coupling line (5) is connected to the connection between the input port A+ (1) and the first open transmission line (13), the C port (1c) of the first parallel coupling line (5) is connected to the C port (3c) of the third parallel coupling line (7), and the D port (1d) of the first parallel coupling line (5) is connected to the first absorption resistor (9); the A port (2a) of the second parallel coupling line (6) is open, the B port (2b) of the second parallel coupling line (6) is connected to the connection between the output port B+ (2) and the second open transmission line (14), the C port (2c) of the second parallel coupling line (6) is connected to the C port (4c) of the fourth parallel coupling line (8), and the second The D port (2d) of the parallel coupling line (6) is connected to the second absorption resistor (10); the A port (3a) of the third parallel coupling line (7) is open, the B port (3b) of the third parallel coupling line (7) is connected to the connection between the input port A- (3) and the third open transmission line (15), the C port (3c) of the third parallel coupling line (7) is connected to the C port (1c) of the first parallel coupling line (5), and the D port (3d) of the third parallel coupling line (7) is open. The fourth parallel coupling line (8) is connected to the third absorption resistor (11); the A port (4a) of the fourth parallel coupling line (8) is open, the B port (4b) of the fourth parallel coupling line (8) is connected to the connection between the output port B- (4) and the fourth open transmission line (16), the C port (4c) of the fourth parallel coupling line (8) is connected to the C port (2c) of the second parallel coupling line (6), and the D port (4d) of the fourth parallel coupling line (8) is connected to the fourth absorption resistor (12); The four absorption resistors include a first absorption resistor (9), a second absorption resistor (10), a third absorption resistor (11), and a fourth absorption resistor (12); wherein one end of the first absorption resistor (9) is connected to the D port (1d) of the first parallel coupling line (5), and the other end is grounded; one end of the second absorption resistor (10) is connected to the D port (2d) of the second parallel coupling line (6), and the other end is grounded; one end of the third absorption resistor (11) is connected to the D port (3d) of the third parallel coupling line (7), and the other end is grounded; one end of the fourth absorption resistor (12) is connected to the D port (4d) of the fourth parallel coupling line (12), and the other end is grounded; The four half-wavelength open-circuit transmission lines include a first open-circuit transmission line (13), a second open-circuit transmission line (14), a third open-circuit transmission line (15), and a fourth open-circuit transmission line (16); wherein the first open-circuit transmission line (13) includes a first microstrip transmission line (131) and a second microstrip transmission line (132); the second open-circuit transmission line (14) includes a third microstrip transmission line (141) and a fourth microstrip transmission line (142); the third open-circuit transmission line (15) includes a first microstrip transmission line (131) and a second microstrip transmission line (132); the third open-circuit transmission line (15) includes a second microstrip transmission line (132) and a third microstrip transmission line (132) and a fourth microstrip transmission line (16). The first microstrip transmission line (131) includes a fifth microstrip transmission line (151) and a sixth microstrip transmission line (152); the fourth open-circuit transmission line (16) includes a seventh microstrip transmission line (161) and an eighth microstrip transmission line (162); one end of the first microstrip transmission line (131) is connected to the connection between the first parallel coupling line (5) and the input port A+ (1), and the other end is connected to the second microstrip transmission line (132); one end of the second microstrip transmission line (132) is connected to the first microstrip transmission line (131). 1) One end is connected to the other end, and the other end is open-circuited; one end of the third microstrip transmission line (141) is connected to the connection between the second parallel coupling line (6) and the output port B+ (2), and the other end is connected to the fourth microstrip transmission line (142); one end of the fourth microstrip transmission line (142) is connected to the third microstrip transmission line (141), and the other end is open-circuited; one end of the fifth microstrip transmission line (151) is connected to the connection between the third parallel coupling line (7) and the input port A- (3), and the other end is open-circuited. One end of the seventh microstrip transmission line (161) is connected to the sixth microstrip transmission line (152); one end of the sixth microstrip transmission line (152) is connected to the fifth microstrip transmission line (151), and the other end is open; one end of the seventh microstrip transmission line (161) is connected to the connection between the fourth parallel coupling line (8) and the output port B- (4), and the other end is connected to the eighth microstrip transmission line (162); one end of the eighth microstrip transmission line (162) is connected to the seventh microstrip transmission line (161), and the other end is open; The two-segment three-wavelength resonant microstrip lines include a first resonant microstrip line (17) and a second resonant microstrip line (18); wherein the first resonant microstrip line (17) includes a first coupled resonant microstrip line (171), a second coupled resonant microstrip line (172), a third coupled resonant microstrip line (173), a fourth coupled resonator microstrip line (174), and a fifth coupled resonant microstrip line (175); The second resonant microstrip line (18) includes a sixth coupled resonant microstrip line (181), a seventh coupled resonant microstrip line (182), an eighth coupled resonant microstrip line (183), a ninth coupled resonator microstrip line (184), and a tenth coupled resonant microstrip line (185); One end of the first coupled resonant microstrip line (171) is connected to the second coupled resonant microstrip line (172), and the other end is open. One end of the second coupled resonant microstrip line (172) is connected to the first coupled resonant microstrip line (171), and the other end is connected to the third coupled resonant microstrip line (173); one end of the third coupled resonant microstrip line (173) is connected to the second coupled resonant microstrip line (172), and the other end is connected to the fourth coupled resonant microstrip line (174); one end of the fourth coupled resonant microstrip line (174) is connected to the third coupled resonant microstrip line (173), and the other end is connected to the fifth coupled resonant microstrip line (175); one end of the fifth coupled resonant microstrip line (175) is connected to the fourth coupled resonant microstrip line (174), and the other end is open-circuited; One end of the sixth coupled resonant microstrip line (181) is connected to the seventh coupled resonant microstrip line (182), and the other end is open; one end of the seventh coupled resonant microstrip line (182) is connected to the sixth coupled resonant microstrip line (181), and the other end is connected to the eighth coupled resonant microstrip line (183); One end of the eighth coupled resonant microstrip line (183) is connected to the seventh coupled resonant microstrip line (182), and the other end is connected to the ninth coupled resonant microstrip line (184); One end of the ninth coupled resonant microstrip line (184) is connected to the eighth coupled resonant microstrip line (183), and the other end is connected to the tenth coupled resonant microstrip line (185); one end of the tenth coupled resonant microstrip line (185) is connected to the ninth coupled resonant microstrip line (184), and the other end is open. The two time-modulated resonant microstrip lines include a first time-modulated resonant microstrip line (19) and a second time-modulated resonant microstrip line (20); wherein the first time-modulated resonant microstrip line (19) includes a first time-modulated coupled resonant microstrip line (191), a second time-modulated coupled resonant microstrip line (192), a third time-modulated coupled resonant microstrip line (193), a fourth time-modulated coupled resonant microstrip line (194), a fifth time-modulated coupled resonant microstrip line (195), and a sixth time-modulated coupled resonant microstrip line (196); the second time-modulated resonant microstrip line (20) includes a seventh time-modulated coupled resonant microstrip line (201), an eighth time-modulated coupled resonant microstrip line (202), a ninth time-modulated coupled resonant microstrip line (203), and a ninth time-modulated coupled resonant microstrip line (204). Ten time-modulated coupled resonant microstrip lines (204), eleventh time-modulated coupled resonant microstrip lines (205), and twelfth time-modulated coupled resonant microstrip lines (206); one end of the first time-modulated coupled resonant microstrip line (191) is connected to the anode of the first varactor diode (21), and the other end is grounded; one end of the second time-modulated coupled resonant microstrip line (192) is connected to the cathode of the first varactor diode (21), and the other end is connected to the third time-modulated coupled resonant microstrip line (193); one end of the third time-modulated coupled resonant microstrip line (193) is connected to the second time-modulated coupled resonant microstrip line (192), and the other end is connected to the connection between the fourth time-modulated coupled resonant microstrip line (194) and the first feed microstrip line (25); One end of the fourth time-modulated coupled resonant microstrip line (194) is connected to the fifth time-modulated coupled resonant microstrip line (195), and the other end is connected to the connection between the third time-modulated coupled resonant microstrip line (193) and the first feed microstrip line (25). One end of the fifth time-modulated coupled resonant microstrip line (195) is connected to the fourth time-modulated coupled resonant microstrip line (194), and the other end is connected to the cathode of the second varactor diode (22); one end of the sixth time-modulated coupled resonant microstrip line (196) is connected to the anode of the second varactor diode (22), and the other end is grounded; one end of the seventh time-modulated coupled resonant microstrip line (201) is connected to the anode of the third varactor diode (23), and the other end is grounded; one end of the eighth time-modulated coupled resonant microstrip line (202) is connected to the cathode of the third varactor diode (23), and the other end is connected to the ninth time-modulated coupled resonant microstrip line (203); one end of the ninth time-modulated coupled resonant microstrip line (203) is connected to the eighth time-modulated coupled resonant microstrip line (202), and the other end is connected to the junction of the tenth time-modulated coupled resonant microstrip line (204) and the second feed microstrip line (26); One end of the tenth time-modulated coupled resonant microstrip line (204) is connected to the eleventh time-modulated coupled resonant microstrip line (205), and the other end is connected to the junction of the ninth time-modulated coupled resonant microstrip line (203) and the second feed microstrip line (26); one end of the eleventh time-modulated coupled resonant microstrip line (205) is connected to the tenth time-modulated coupled resonant microstrip line (204), and the other end is connected to the cathode of the fourth varactor diode (24); one end of the twelfth time-modulated coupled resonant microstrip line (206) is connected to the anode of the fourth varactor diode (22), and the other end is grounded; The four varactor diodes include a first varactor diode (21), a second varactor diode (22), a third varactor diode (23), and a fourth varactor diode (24); wherein the anode of the first varactor diode (21) is connected to a first time-modulated coupled resonant microstrip line (191), and the cathode of the other end is connected to a second time-modulated coupled resonant microstrip line (192); the anode of the second varactor diode (22) is connected to a sixth time-modulated coupled resonant microstrip line (196), and the cathode of the other end is connected to a fifth time-modulated coupled resonant microstrip line (195); the anode of the third varactor diode (23) is connected to a seventh time-modulated coupled resonant microstrip line (201), and the cathode of the other end is connected to an eighth time-modulated coupled resonant microstrip line (202); the anode of the fourth varactor diode (24) is connected to a twelfth time-modulated coupled resonant microstrip line (206), and the cathode of the other end is connected to an eleventh time-modulated coupled resonant microstrip line (205); The two quarter-wavelength fed microstrip lines include a first fed microstrip line (25) and a second fed microstrip line (26); wherein one end of the first fed microstrip line (25) is connected to the connection between the third time-modulated coupled resonant microstrip line (193) and the fourth time-modulated coupled resonant microstrip line (194), and the other end is connected to the first power supply (27); one end of the second fed microstrip line (26) is connected to the connection between the ninth time-modulated coupled resonant microstrip line (203) and the tenth time-modulated coupled resonant microstrip line (204), and the other end is connected to the second power supply (28); The two power supplies include a first power supply (27) and a second power supply (28); wherein the first power supply (27) is connected to a first feed microstrip line (25); and the second power supply (28) is connected to a second feed microstrip line (26). The second microstrip transmission line (132) and the second coupled resonant microstrip line (172) are both quarter-wavelength, parallel to each other, and have a coupling effect; the fourth microstrip transmission line (142) and the seventh coupled resonant microstrip line (182) are both quarter-wavelength, parallel to each other, and have a coupling effect; the sixth microstrip transmission line (152) and the fourth coupled resonant microstrip line (174) are both quarter-wavelength, parallel to each other, and have a coupling effect. The eighth microstrip transmission line (162) and the ninth coupled resonant microstrip line (184) are both quarter wavelengths, parallel to each other, and have a coupling effect; The first coupled resonant microstrip line (171) and the third time-modulated coupled resonant microstrip line (193) are both quarter wavelengths, parallel to each other and have a coupling effect; The sixth coupled resonant microstrip line (181) and the ninth time-modulated coupled resonant microstrip line (203) are both quarter wavelengths, parallel to each other and have a coupling effect; the fifth coupled resonant microstrip line (175) and the fourth time-modulated coupled resonant microstrip line (194) are both quarter wavelengths, parallel to each other and have a coupling effect. The tenth coupled resonant microstrip line (185) and the tenth time-modulated coupled resonant microstrip line (204) are both quarter wavelengths, parallel to each other and have a coupling effect; The second time-modulated coupled resonant microstrip line (192) and the eighth time-modulated coupled resonant microstrip line (202) are both quarter wavelengths, parallel to each other and have a coupling effect; the fifth time-modulated coupled resonant microstrip line (195) and the eleventh time-modulated coupled resonant microstrip line (205) are both quarter wavelengths, parallel to each other and have a coupling effect.

2. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics according to claim 1, characterized in that: By adjusting the DC voltage V output by the first power supply (27) dc AC voltage amplitude V ac Frequency f m Initial phase DC voltage V output by the second power supply (28) dc AC voltage amplitude V ac Frequency f m Initial phase By completing time modulation, controlling the transmission of the forward differential signal, and simultaneously cutting off the reverse differential signal, the non-reciprocity of a balanced tapeless pass-through filter with differential and common-mode non-reflection characteristics is achieved.

3. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics according to claim 1, characterized in that: The first power supply (27) and the second power supply (28) only output DC voltage V dc At this time, the filter is a balanced reciprocal bandpass filter with differential and common-mode non-reflection characteristics.

4. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics according to claim 1, characterized in that: By adjusting the odd-mode and even-mode characteristic impedances of the first parallel coupling line (5), the odd-mode and even-mode characteristic impedances of the second parallel coupling line (6), the odd-mode and even-mode characteristic impedances of the third parallel coupling line (7), the odd-mode and even-mode characteristic impedances of the fourth parallel coupling line (8), the resistance values ​​of the first absorption resistor (9), the second absorption resistor (10), the third absorption resistor (11), and the fourth absorption resistor (12), the differential-mode and common-mode non-reflective absorption characteristics of the balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflective characteristics can be adjusted.

5. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics according to claim 1, characterized in that: The coupling between the second microstrip transmission line (132) and the second coupled resonant microstrip line (172), the coupling between the fourth microstrip transmission line (142) and the seventh coupled resonant microstrip line (182), the coupling between the sixth microstrip transmission line (152) and the fourth coupled resonant microstrip line (174), and the coupling between the eighth microstrip transmission line (162) and the ninth coupled resonant microstrip line (184) exhibit a full-resistance response under common-mode signal excitation, thereby achieving common-mode suppression characteristics.

6. A balanced, non-magnetic, non-reciprocal bandpass filter with differential-mode and common-mode reflection-free characteristics according to claim 1, characterized in that: By adjusting the characteristic impedance of the four half-wavelength open-circuit transmission lines, the distance between the second microstrip transmission line (132) and the second coupled resonant microstrip line (172), the distance between the fourth microstrip transmission line (142) and the seventh coupled resonant microstrip line (182), the distance between the sixth microstrip transmission line (152) and the fourth coupled resonant microstrip line (174), the distance between the eighth microstrip transmission line (162) and the ninth coupled resonant microstrip line (184), the distance between the first coupled resonant microstrip line (171) and the third time-modulated coupled resonant microstrip line (193), and the distance between the sixth coupled resonant microstrip line (181) and the ninth time-modulated coupled resonant microstrip line (193), the distance between the first coupled resonant microstrip line (171) and the third time-modulated coupled resonant microstrip line (193) is increased. The distances between the strip lines (203), the fifth coupled resonant microstrip line (175) and the fourth time-modulated coupled resonant microstrip line (194), the tenth coupled resonant microstrip line (185) and the tenth time-modulated coupled resonant microstrip line (204), the second time-modulated coupled resonant microstrip line (192) and the eighth time-modulated coupled resonant microstrip line (202), and the fifth time-modulated coupled resonant microstrip line (195) and the eleventh time-modulated coupled resonant microstrip line (205) are adjusted to regulate the passband bandwidth and frequency selectivity of a balanced non-magnetic non-reciprocal bandpass filter with differential-mode and common-mode non-reflective characteristics.

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