An absorptive balanced filter power divider with arbitrary transmission zero point

Abstract

The present invention provides an absorption-type balanced filter power divider with arbitrary transmission zero point, which relates to the field of communication technology and is constructed on a printed circuit board, comprising: a microstrip unit, a dielectric substrate and a metal ground arranged in sequence from top to bottom; a first absorption network, a first low-pass filter unit, a second absorption network, a second low-pass filter unit, a third low-pass filter unit, a third absorption network and a fourth low-pass filter unit are integrated on the microstrip unit, and the first absorption network, the first low-pass filter unit, the second absorption network, the second low-pass filter unit, the third low-pass filter unit, the third absorption network and the fourth low-pass filter unit are sequentially connected end to end to form a closed loop. The technical solution of the present invention overcomes the problems in the prior art that the common mode noise reflected by the balanced port cannot be absorbed and the suppression effect on unnecessary frequency bands is poor.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an absorption-type balanced filtering power divider with an arbitrary transmission zero point. Background Art

[0002] As a basic three-port passive device, the power divider can realize power distribution and combined control, and is widely used in communication, broadcasting, radar, electronic countermeasures and other fields. Filters, as key frequency selection components, such as low-pass and band-pass filters, are widely used in RF front-end circuits to eliminate unwanted image frequencies and noise signals. With the widespread application of multi-band and multi-standard systems, multi-functional integrated system designs have gradually replaced traditional multi-channel parallel integrated systems, which not only simplifies the complexity of the circuit, but also significantly improves the circuit performance. In addition, compared with single-port circuits, balanced circuits can provide higher resistance to environmental noise and wider common-mode suppression bandwidth. However, in traditional balanced circuits, although the common-mode noise is completely reflected at the input port and cannot be transmitted to the output port, it still exists in the system and may cause electromagnetic interference, thereby affecting the performance of the entire system.

[0003] Therefore, there is a need for an absorptive balanced filter power divider with an arbitrary transmission zero point that can absorb the common mode noise reflected by the balanced port and enhance the suppression effect on unnecessary frequency bands. Summary of the invention

[0004] The main purpose of the present invention is to provide an absorption-type balanced filter power divider with an arbitrary transmission zero point to solve the problems in the prior art that the common-mode noise reflected by the balanced port cannot be absorbed and the suppression effect on unnecessary frequency bands is poor.

[0005] To achieve the above-mentioned purpose, the present invention provides an absorption-type balanced filtering power divider with an arbitrary transmission zero point, which is constructed on a printed circuit board and includes: a microstrip unit, a dielectric substrate and a metal ground arranged in sequence from top to bottom; a first absorption network, a first low-pass filtering unit, a second absorption network, a second low-pass filtering unit, a third low-pass filtering unit, a third absorption network and a fourth low-pass filtering unit are integrated on the microstrip unit, and the first absorption network, the first low-pass filtering unit, the second absorption network, the second low-pass filtering unit, the third low-pass filtering unit, the third absorption network and the fourth low-pass filtering unit are connected end to end in sequence to form a closed loop.

[0006] Furthermore, the first absorption network includes: a first rectangular microstrip line, a first bent rectangular microstrip line, a second rectangular microstrip line and a first branch line, the first rectangular microstrip line, the first bent rectangular microstrip line, the second rectangular microstrip line and the first branch line are connected end to end; the first rectangular microstrip line is connected to the first input port through the first feeder, and the second rectangular microstrip line is connected to the fourth input port through the second feeder; the upper end of the first bent rectangular microstrip line is connected to the intersection of the first rectangular microstrip line and the first feeder, and the lower end of the first bent rectangular microstrip line is connected to the intersection of the second rectangular microstrip line and the second feeder; the first absorption network also includes a second bent rectangular microstrip line, the second bent rectangular microstrip line is arranged in parallel with the first bent rectangular microstrip line, and forms an open-circuit coupled line structure.

[0007] Furthermore, the second absorption network includes: a third rectangular microstrip line, a second branch line, a fourth rectangular microstrip line and a first concave microstrip line, the third rectangular microstrip line, the second branch line, the fourth rectangular microstrip line and the first concave microstrip line are connected end to end; the third rectangular microstrip line is connected to the second input port through a third feeder, and the fourth rectangular microstrip line is connected to the third input port through a fourth feeder; the left end of the first concave microstrip line is connected to the intersection of the third rectangular microstrip line and the third feeder, and the right end of the first concave microstrip line is connected to the intersection of the fourth rectangular microstrip line and the fourth feeder; the second absorption network also includes a second concave microstrip line, which is arranged in parallel with the first concave microstrip line to form an open-circuit coupled line structure.

[0008] Furthermore, the third absorption network includes: a fifth rectangular microstrip line, a first convex microstrip line, a sixth rectangular microstrip line and a third branch line, the fifth rectangular microstrip line, the first convex microstrip line, the sixth rectangular microstrip line and the third branch line are connected end to end; the fifth rectangular microstrip line is connected to the fifth input port through the fifth feeder, and the sixth rectangular microstrip line is connected to the sixth input port through the sixth feeder; the left end of the first convex microstrip line is connected to the intersection of the fifth rectangular microstrip line and the fifth feeder, and the right end of the first convex microstrip line is connected to the intersection of the sixth rectangular microstrip line and the sixth feeder; the third absorption network also includes: a second convex microstrip line, the second convex microstrip line is arranged in parallel with the first convex microstrip line, and forms an open-circuit coupled line structure.

[0009] Furthermore, the line widths and line lengths of the first branch line, the second branch line and the third branch line are exactly the same; the first bent rectangular microstrip line and the second bent rectangular microstrip line, the first concave microstrip line and the second concave microstrip line, and the first convex microstrip line and the second convex microstrip line form three groups of coupling lines, and the line width, line length and line spacing of each group of coupling lines are exactly the same.

[0010] Further, the first low-pass filtering unit includes: a seventh rectangular microstrip line, an eighth rectangular microstrip line, a ninth rectangular microstrip line, a first right-angled trapezoidal microstrip line, a second right-angled trapezoidal microstrip line, a tenth rectangular microstrip line, an eleventh rectangular microstrip line, a twelfth rectangular microstrip line, a thirteenth rectangular microstrip line, a first E-shaped microstrip line and a first ram's horn microstrip line; the first rectangular microstrip line, the seventh rectangular microstrip line, the eighth rectangular microstrip line, the ninth rectangular microstrip line and the second branch line are connected in sequence, the first right-angled trapezoidal microstrip line and the second right-angled trapezoidal microstrip line are respectively connected to the ends of the ninth rectangular microstrip line and the seventh rectangular microstrip line; the twelfth rectangular microstrip line is connected at the intersection of the second right-angled trapezoidal microstrip line and the eleventh rectangular microstrip line, and the thirteenth rectangular microstrip line is connected at the intersection of the first right-angled trapezoidal microstrip line and the tenth rectangular microstrip line; the midpoints of the first E-shaped microstrip line and the first ram's horn microstrip line are respectively connected to the twelfth rectangular microstrip line and the thirteenth rectangular microstrip line.

[0011] Further, the second low-pass filtering unit includes: a fourteenth rectangular microstrip line, a fifteenth rectangular microstrip line, a sixteenth rectangular microstrip line, a third right-angled trapezoidal microstrip line, a fourth right-angled trapezoidal microstrip line, a seventeenth rectangular microstrip line, an eighteenth rectangular microstrip line, a nineteenth rectangular microstrip line, a twentieth rectangular microstrip line, a second E-shaped microstrip line and a second ram-shaped microstrip line; the fourth rectangular microstrip line, the fourteenth rectangular microstrip line, the fifteenth rectangular microstrip line and the sixteenth rectangular microstrip line are connected in sequence, the third right-angled trapezoidal microstrip line and the fourth right-angled trapezoidal microstrip line are respectively connected to the ends of the sixteenth rectangular microstrip line and the fourteenth rectangular microstrip line; the nineteenth rectangular microstrip line is connected at the intersection of the fourth right-angled trapezoidal microstrip line and the eighteenth rectangular microstrip line, and the twentieth rectangular microstrip line is connected at the intersection of the third right-angled trapezoidal microstrip line and the seventeenth rectangular microstrip line; the midpoints of the second E-shaped microstrip line and the second ram-shaped microstrip line are respectively connected to the nineteenth rectangular microstrip line and the twentieth rectangular microstrip line.

[0012] Further, the third low-pass filtering unit includes: a twenty-first rectangular microstrip line, a twenty-second rectangular microstrip line, a twenty-third rectangular microstrip line, a fifth right-angled trapezoidal microstrip line, a sixth right-angled trapezoidal microstrip line, a twenty-fourth rectangular microstrip line, a twenty-fifth rectangular microstrip line, a twenty-sixth rectangular microstrip line, a twenty-seventh rectangular microstrip line, a third E-shaped microstrip line and a third ram-shaped microstrip line; a sixth rectangular microstrip line, a twenty-third rectangular microstrip line, a twenty-second rectangular microstrip line, a twenty-first rectangular microstrip line and a sixteenth rectangular microstrip line Connected in sequence, the fifth right-angled trapezoidal microstrip line and the sixth right-angled trapezoidal microstrip line are connected to the ends of the twenty-first rectangular microstrip line and the twenty-third rectangular microstrip line respectively; the twenty-sixth rectangular microstrip line is connected at the intersection of the fifth right-angled trapezoidal microstrip line and the twenty-fourth rectangular microstrip line, and the twenty-seventh rectangular microstrip line is connected at the intersection of the twenty-fifth rectangular microstrip line and the sixth right-angled trapezoidal microstrip line; the midpoints of the third E-shaped microstrip line and the third ram's horn microstrip line are connected to the twenty-sixth rectangular microstrip line and the twenty-seventh rectangular microstrip line respectively.

[0013] Further, the fourth low-pass filtering unit includes: a twenty-eighth rectangular microstrip line, a twenty-ninth rectangular microstrip line, a thirtieth rectangular microstrip line, a seventh right-angled trapezoidal microstrip line, an eighth right-angled trapezoidal microstrip line, a thirty-first rectangular microstrip line, a thirty-second rectangular microstrip line, a thirty-third rectangular microstrip line, a thirty-fourth rectangular microstrip line, a fourth E-shaped microstrip line and a fourth ram-shaped microstrip line; the thirty-fourth rectangular microstrip line is connected at the intersection of the eighth right-angled trapezoidal microstrip line and the thirty-second rectangular microstrip line, and the thirty-third rectangular microstrip line is connected at the intersection of the seventh right-angled trapezoidal microstrip line and the thirty-third rectangular microstrip line; the second rectangular microstrip line, the thirty-first rectangular microstrip line, the thirty-second rectangular microstrip line, the thirty-third rectangular microstrip line, the fourth E-shaped microstrip line and the fourth ram-shaped microstrip line The rectangular microstrip line, the twenty-ninth rectangular microstrip line, the twenty-eighth rectangular microstrip line and the third branch line are connected in sequence, wherein the seventh right-angled trapezoidal microstrip line and the eighth right-angled trapezoidal microstrip line are connected to the ends of the twenty-eighth rectangular microstrip line and the thirtieth rectangular microstrip line respectively; the thirty-third rectangular microstrip line is connected at the intersection of the seventh right-angled trapezoidal microstrip line and the thirty-first rectangular microstrip line, and the thirty-fourth rectangular microstrip line is connected at the intersection of the eighth right-angled trapezoidal microstrip line and the thirty-second rectangular microstrip line; wherein the midpoints of the fourth E-shaped microstrip line and the fourth ram's horn microstrip line are connected to the thirty-third rectangular microstrip line and the thirty-fourth rectangular microstrip line respectively.

[0014] Furthermore, it also includes: a first absorption resistor, a second absorption resistor, a third absorption resistor and an isolation resistor, one end of the first absorption resistor is welded to the thirty-fifth rectangular microstrip line, the thirty-fifth rectangular microstrip line is welded at the midpoint of the second bent rectangular microstrip line, and the other end of the first absorption resistor is welded to the first metal via and then grounded; one end of the second absorption resistor is welded to the thirty-sixth rectangular microstrip line, the thirty-sixth rectangular microstrip line is welded at the midpoint of the second concave microstrip line, the other end of the second absorption resistor is welded to the second metal via and then grounded, one end of the third absorption resistor is welded to the thirty-seventh rectangular microstrip line, the thirty-seventh rectangular microstrip line is welded at the midpoint of the second convex microstrip line, the other end of the third absorption resistor is welded to the third metal via and then grounded, one end of the isolation resistor is welded to the thirty-eighth rectangular microstrip line, the thirty-eighth rectangular microstrip line is welded at the midpoint of the sixteenth rectangular microstrip line and the twenty-first rectangular microstrip line, and the other end of the isolation resistor is welded to the fourth metal via and then grounded.

[0015] The present invention has the following beneficial effects:

[0016] Multifunctional integration: The present invention integrates the filter, balanced power divider and common-mode noise absorption network into one device for the first time. While realizing the filtering and power division functions, it can also absorb the common-mode noise reflected by the balanced input port, thus improving the overall performance of the system. The present invention is easy to integrate with other circuits through planar design and integrated design, which reduces the volume and complexity of the entire system and is conducive to miniaturization and portable applications;

[0017] Transmission zero point control problem: It is difficult for traditional balanced power dividers to accurately control the position of the transmission zero point, which affects the frequency selectivity and signal interference suppression capabilities. The present invention enhances the suppression effect of unnecessary frequency bands by controlling the transmission zero point design;

[0018] Good common-mode noise absorption characteristics: The present invention realizes the absorption filtering balanced power divider for the first time. Compared with the latest absorption balanced power divider without filtering characteristics, it not only has higher functional integration, but also has more than ten times the common-mode return loss, insertion loss and isolation bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the specific implementation or the prior art description. Obviously, the drawings described below are some implementations of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 The overall structural schematic diagram of an absorption-type balanced filtering power divider with an arbitrary transmission zero point of the present invention is shown.

[0021] Figure 2 A schematic diagram of the integrated module structure on a microstrip unit is shown.

[0022] Figure 3 A comparison diagram of the amplitude response results of the simulation and the test of the absorptive balanced filter power divider provided by the present invention in the differential mode state is shown.

[0023] Figure 4 A comparison diagram of the amplitude response results of the simulation and the test of the absorptive balanced filtering power divider provided by the present invention in the differential mode and common mode conversion states is shown.

[0024] Figure 5 A comparison diagram of the amplitude response results of the simulation and the test of the absorptive balanced filter power divider provided by the present invention under the common mode state is shown.

[0025] Figure 6 A comparison diagram of the amplitude response results of the differential mode phase difference simulation and test of the absorptive balanced filtering power divider provided by the present invention.

[0026] The reference numerals in the above drawings are:

[0027] 1. Microstrip unit; 2. Dielectric substrate; 3. Metal ground; 10. First input port; 20. Second input port; 30. Third input port; 40. Fourth input port; 50. Fifth input port; 60. Sixth input port; 41. First low-pass filter unit; 42. Second low-pass filter unit; 43. Third low-pass filter unit; 44. Fourth low-pass filter unit; 51. First absorption network; 52. Second absorption network; 53. Third absorption network; 11. First feeder; 12. Third feeder; 13. Fourth feeder; 14. Second feeder; 15. Fifth feeder; 16. Sixth feeder; 111. First branch line; 112. Second branch line; 113. Third branch line; 123. First rectangular microstrip line; 1 28, second rectangular microstrip line; 124, third rectangular microstrip line; 125, fourth rectangular microstrip line; 127, fifth rectangular microstrip line; 126, sixth rectangular microstrip line; 401, seventh rectangular microstrip line; 402, eighth rectangular microstrip line; 403, ninth rectangular microstrip line; 405, tenth rectangular microstrip line; 406, eleventh rectangular microstrip line; 408, twelfth rectangular microstrip line; 409, thirteenth rectangular microstrip line; 412, fourteenth rectangular microstrip line; 413, fifteenth rectangular microstrip line; 414, sixteenth rectangular microstrip line; 416, seventeenth rectangular microstrip line; 417, eighteenth rectangular microstrip line; 419, nineteenth rectangular microstrip line; 422, twentieth rectangular microstrip line; 423, twenty-first rectangular microstrip line ; 424, the twenty-second rectangular microstrip line; 425, the twenty-third rectangular microstrip line; 426, the twenty-fourth rectangular microstrip line; 432, the twenty-fifth rectangular microstrip line; 428, the twenty-sixth rectangular microstrip line; 431, the twenty-seventh rectangular microstrip line; 434, the twenty-eighth rectangular microstrip line; 435, the twenty-ninth rectangular microstrip line; 436, the thirtieth rectangular microstrip line; 438, the thirty-first rectangular microstrip line; 443, the thirty-second rectangular microstrip line; 439, the thirty-third rectangular microstrip line; 444, the thirty-fourth rectangular microstrip line; 116, the thirty-fifth rectangular microstrip line; 119, the thirty-sixth rectangular microstrip line; 122, the thirty-seventh rectangular microstrip line; 129, the thirty-eighth rectangular microstrip line; 114, the first bent rectangular microstrip Line; 115, second bent rectangular microstrip line; 118, first concave microstrip line; 117, second concave microstrip line; 120, first convex microstrip line; 121, second convex microstrip line; 404, first right-angle trapezoidal microstrip line; 407, second right-angle trapezoidal microstrip line; 415, third right-angle trapezoidal microstrip line; 418, fourth right-angle trapezoidal microstrip line; 427, fifth right-angle trapezoidal microstrip line; 433, sixth right-angle trapezoidal microstrip line; 437, seventh right-angle trapezoidal microstrip line; 442, eighth right-angle trapezoidal microstrip line; 410, first E-shaped microstrip line; 420, second E-shaped microstrip line; 429, third E-shaped microstrip line; 440, fourth E-shaped microstrip line; 411, first ram's horn microstrip line; 421, second ram's horn microstrip line;430, third ram's horn microstrip line; 441, fourth ram's horn microstrip line; 31, first absorption resistor; 32, second absorption resistor; 33, isolation resistor; 34, third absorption resistor; 21, first metal via; 22, second metal via; 24, third metal via; 23, fourth metal via. ; DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1 and Figure 2 An absorption balanced filtering power divider with an arbitrary transmission zero point shown is constructed on a printed circuit board, and includes: a microstrip unit 1, a dielectric substrate 2 and a metal ground 3 arranged in sequence from top to bottom; a first absorption network 51, a first low-pass filtering unit 41, a second absorption network 52, a second low-pass filtering unit 42, a third low-pass filtering unit 43, a third absorption network 53 and a fourth low-pass filtering unit 44 are integrated on the microstrip unit, and the first absorption network 51, the first low-pass filtering unit 41, the second absorption network 52, the second low-pass filtering unit 42, the third low-pass filtering unit 43, the third absorption network 53 and the fourth low-pass filtering unit 44 are connected end to end in sequence to form a closed loop.

[0030] Specifically, the first absorption network 51 includes: a first rectangular microstrip line 123, a first bent rectangular microstrip line 114, a second rectangular microstrip line 128 and a first branch line 111, wherein the first rectangular microstrip line 123, the first bent rectangular microstrip line 114, the second rectangular microstrip line 128 and the first branch line 111 are connected end to end; the first rectangular microstrip line 123 is connected to the first input port 10 through the first feeder 11, and the second rectangular microstrip line 128 is connected to the fourth input port 40 through the second feeder 14; the upper end of the first bent rectangular microstrip line 114 is connected to the intersection of the first rectangular microstrip line 123 and the first feeder 11, and the lower end of the first bent rectangular microstrip line 114 is connected to the intersection of the second rectangular microstrip line 128 and the second feeder 14; the first absorption network 51 also includes a second bent rectangular microstrip line 115, which is arranged in parallel with the first bent rectangular microstrip line 114 to form an open-circuit coupled line structure.

[0031] Specifically, the second absorption network 52 includes: a third rectangular microstrip line 124, a second branch line 112, a fourth rectangular microstrip line 125 and a first concave microstrip line 118, the third rectangular microstrip line 124, the second branch line 112, the fourth rectangular microstrip line 125 and the first concave microstrip line 118 are connected end to end; the third rectangular microstrip line 124 is connected to the second input port 20 through the third feeder 12, and the fourth rectangular microstrip line 125 is connected to the third input port 30 through the fourth feeder 13; the left end of the first concave microstrip line 118 is connected to the intersection of the third rectangular microstrip line 124 and the third feeder 12, and the right end of the first concave microstrip line 118 is connected to the intersection of the fourth rectangular microstrip line 125 and the fourth feeder 13; the second absorption network 52 also includes a second concave microstrip line 117, the second concave microstrip line 117 is arranged in parallel with the first concave microstrip line 118, and forms an open-circuit coupled line structure.

[0032] Specifically, the third absorption network 53 includes: a fifth rectangular microstrip line 127, a first convex microstrip line 120, a sixth rectangular microstrip line 126 and a third branch line 113, wherein the fifth rectangular microstrip line 127, the first convex microstrip line 120, the sixth rectangular microstrip line 126 and the third branch line 113 are connected end to end; the fifth rectangular microstrip line 127 is connected to the fifth input port 50 through the fifth feeder 15, and the sixth rectangular microstrip line 126 is connected to the sixth input port 60 through the sixth feeder 16; the left end of the first convex microstrip line 120 is connected to the intersection of the fifth rectangular microstrip line 127 and the fifth feeder 15, and the right end of the first convex microstrip line 120 is connected to the intersection of the sixth rectangular microstrip line 126 and the sixth feeder 16; the third absorption network 53 also includes: a second convex microstrip line 121, which is arranged in parallel with the first convex microstrip line 120 to form an open-circuit coupled line structure.

[0033] The second bent rectangular microstrip line 115, the second concave microstrip line 117 and the second convex microstrip line 121 are welded on the dielectric substrate 2. Specifically, the first input port and the fourth input port constitute a first balanced port A, the second input port and the third input port constitute a second balanced port B, the fifth input port and the sixth input port constitute a third balanced port C, and the first input port and the fourth input port constitute a fourth balanced port D.

[0034] Specifically, the line width and line length of the first branch line 111, the second branch line 112 and the third branch line 113 are exactly the same; the first bent rectangular microstrip line 114 and the second bent rectangular microstrip line 115, the first concave microstrip line 118 and the second concave microstrip line 117, and the first convex microstrip line 120 and the second convex microstrip line 121 form three groups of coupling lines, and the line width, line length and line spacing of each group of coupling lines are exactly the same.

[0035] Specifically, the first low-pass filtering unit 41 includes: a seventh rectangular microstrip line 401, an eighth rectangular microstrip line 402, a ninth rectangular microstrip line 403, a first right-angled trapezoidal microstrip line 404, a second right-angled trapezoidal microstrip line 407, a tenth rectangular microstrip line 405, an eleventh rectangular microstrip line 406, a twelfth rectangular microstrip line 408, a thirteenth rectangular microstrip line 409, a first E-shaped microstrip line 410 and a first ram-shaped microstrip line 411; the first rectangular microstrip line 123, the seventh rectangular microstrip line 401, the eighth rectangular microstrip line 402, the ninth rectangular microstrip line 403 and the second branch line 112 are connected in accordance with the present invention. The first right-angled trapezoidal microstrip line 404 and the second right-angled trapezoidal microstrip line 407 are connected to the ends of the ninth rectangular microstrip line 403 and the seventh rectangular microstrip line 401 respectively; the twelfth rectangular microstrip line 408 is connected to the intersection of the second right-angled trapezoidal microstrip line 407 and the eleventh rectangular microstrip line 406, and the thirteenth rectangular microstrip line 409 is connected to the intersection of the first right-angled trapezoidal microstrip line 404 and the tenth rectangular microstrip line 405; the midpoints of the first E-shaped microstrip line 410 and the first ram-shaped microstrip line 411 are connected to the twelfth rectangular microstrip line 408 and the thirteenth rectangular microstrip line 409 respectively.

[0036] Specifically, the second low-pass filtering unit 42 includes: a fourteenth rectangular microstrip line 412, a fifteenth rectangular microstrip line 413, a sixteenth rectangular microstrip line 414, a third right-angled trapezoidal microstrip line 415, a fourth right-angled trapezoidal microstrip line 418, a seventeenth rectangular microstrip line 416, an eighteenth rectangular microstrip line 417, a nineteenth rectangular microstrip line 419, a twentieth rectangular microstrip line 422, a second E-shaped microstrip line 420 and a second ram-shaped microstrip line 421; the fourth rectangular microstrip line 125, the fourteenth rectangular microstrip line 412, the fifteenth rectangular microstrip line 413 and the sixteenth rectangular microstrip line 414 are arranged in sequence. The third right-angled trapezoidal microstrip line 415 and the fourth right-angled trapezoidal microstrip line 418 are connected to the ends of the sixteenth rectangular microstrip line 414 and the fourteenth rectangular microstrip line 412 respectively; the nineteenth rectangular microstrip line 419 is connected at the intersection of the fourth right-angled trapezoidal microstrip line 418 and the eighteenth rectangular microstrip line 417, and the twentieth rectangular microstrip line 422 is connected at the intersection of the third right-angled trapezoidal microstrip line 415 and the seventeenth rectangular microstrip line 416; the midpoints of the second E-shaped microstrip line 420 and the second ram-shaped microstrip line 421 are connected to the nineteenth rectangular microstrip line 419 and the twentieth rectangular microstrip line 422 respectively.

[0037] Specifically, the third low-pass filtering unit 43 includes: a twenty-first rectangular microstrip line 423, a twenty-second rectangular microstrip line 424, a twenty-third rectangular microstrip line 425, a fifth right-angled trapezoidal microstrip line 427, a sixth right-angled trapezoidal microstrip line 433, a twenty-fourth rectangular microstrip line 426, a twenty-fifth rectangular microstrip line 432, a twenty-sixth rectangular microstrip line 428, a twenty-seventh rectangular microstrip line 431, a third E-shaped microstrip line 429 and a third ram-shaped microstrip line 430; a sixth rectangular microstrip line 426, a twenty-third rectangular microstrip line 425, a twenty-second rectangular microstrip line 424, a twenty-first rectangular microstrip line 423 and a sixth rectangular microstrip line 433 Line 414 is connected in sequence, the fifth right-angled trapezoidal microstrip line 427 and the sixth right-angled trapezoidal microstrip line 433 are connected to the ends of the twenty-first rectangular microstrip line 423 and the twenty-third rectangular microstrip line 425 respectively; the twenty-sixth rectangular microstrip line 428 is connected at the intersection of the fifth right-angled trapezoidal microstrip line 427 and the twenty-fourth rectangular microstrip line 426, and the twenty-seventh rectangular microstrip line 431 is connected at the intersection of the twenty-fifth rectangular microstrip line 432 and the sixth right-angled trapezoidal microstrip line 433; the midpoints of the third E-shaped microstrip line 429 and the third ram's horn microstrip line 430 are connected to the twenty-sixth rectangular microstrip line 428 and the twenty-seventh rectangular microstrip line 431 respectively.

[0038] Specifically, the fourth low-pass filtering unit 44 includes: a twenty-eighth rectangular microstrip line 434, a twenty-ninth rectangular microstrip line 435, a thirtieth rectangular microstrip line 436, a seventh right-angled trapezoidal microstrip line 437, an eighth right-angled trapezoidal microstrip line 442, a thirty-first rectangular microstrip line 438, a thirty-second rectangular microstrip line 443, a thirty-third rectangular microstrip line 439, a thirty-fourth rectangular microstrip line 444, a fourth E-shaped microstrip line 440 and a fourth ram-shaped microstrip line 441; the thirty-fourth rectangular microstrip line 444 is connected at the intersection of the eighth right-angled trapezoidal microstrip line 442 and the thirty-second rectangular microstrip line 443, and the thirty-third rectangular microstrip line 439 is connected at the intersection of the seventh right-angled trapezoidal microstrip line 437 and the thirty-third rectangular microstrip line 439; the second rectangular microstrip line 128, the third The twenty-ninth rectangular microstrip line 436, the twenty-ninth rectangular microstrip line 435, the twenty-eighth rectangular microstrip line 434 and the third branch line 113 are connected in sequence, wherein the seventh right-angled trapezoidal microstrip line 437 and the eighth right-angled trapezoidal microstrip line 442 are connected to the ends of the twenty-eighth rectangular microstrip line 434 and the thirtieth rectangular microstrip line 436 respectively; the thirty-third rectangular microstrip line 439 is connected at the intersection of the seventh right-angled trapezoidal microstrip line 437 and the thirty-first rectangular microstrip line 438, and the thirty-fourth rectangular microstrip line 444 is connected at the intersection of the eighth right-angled trapezoidal microstrip line 442 and the thirty-second rectangular microstrip line 443; wherein the midpoints of the fourth E-shaped microstrip line 440 and the fourth ram's horn microstrip line 441 are connected to the thirty-third rectangular microstrip line 439 and the thirty-fourth rectangular microstrip line 444 respectively.

[0039] Specifically, it also includes: a first absorption resistor 31, a second absorption resistor 32, a third absorption resistor 34 and an isolation resistor 33, one end of the first absorption resistor 31 is welded to the thirty-fifth rectangular microstrip line 116, the thirty-fifth rectangular microstrip line 116 is welded at the midpoint of the second bent rectangular microstrip line 115, the other end of the first absorption resistor 31 is welded to the first metal via 21 and then grounded; one end of the second absorption resistor 32 is welded to the thirty-sixth rectangular microstrip line 119, the thirty-sixth rectangular microstrip line 119 is welded at the midpoint of the second concave microstrip line 117, the other end of the second absorption resistor 32 is welded to the thirty-sixth rectangular microstrip line 119 One end is welded to the second metal via 22 and then grounded, one end of the third absorption resistor 34 is welded to the thirty-seventh rectangular microstrip line 122, the thirty-seventh rectangular microstrip line 122 is welded at the midpoint of the second convex microstrip line 121, the other end of the third absorption resistor 34 is welded to the third metal via 24 and then grounded, one end of the isolation resistor 33 is welded to the thirty-eighth rectangular microstrip line 129, the thirty-eighth rectangular microstrip line 129 is welded at the midpoint of the sixteenth rectangular microstrip line 414 and the twenty-first rectangular microstrip line 423, and the other end of the isolation resistor 33 is welded to the fourth metal via 23 and then grounded.

[0040] The first absorption resistor 31 , the second absorption resistor 32 , the third absorption resistor 34 , and the isolation resistor 33 are implemented by resistors of 51Ω, 51Ω, 51Ω, and 24Ω, respectively.

[0041] The dielectric substrate 2 is made of Rogers RT5880 material with a thickness of 0.508 mm and a relative dielectric constant of 2.2.

[0042] The metal ground 3 is a metal layer uniformly covered with a high-quality conductor (such as copper).

[0043] The working center frequency of the absorption balanced filter power divider provided by the present invention is 2.0 GHz, and the transmission zero point is 4.0 GHz. The transmission zero point of the absorption balanced filter power divider is controlled by controlling the line width and line length of the eighth rectangular microstrip line 402, the fifteenth rectangular microstrip line 413, the twenty-second rectangular microstrip line 424, and the twenty-ninth rectangular microstrip line 435 in the first low-pass filter unit 41, the second low-pass filter unit 42, the third low-pass filter unit 43, and the fourth low-pass filter unit 44, as well as the density of the interdigital structure composed of the first E-shaped microstrip line 410 and the first ram's horn microstrip line 411, the second E-shaped microstrip line 420 and the second ram's horn microstrip line 421, the third E-shaped microstrip line 429 and the third ram's horn microstrip line 430, the fourth E-shaped microstrip line 440 and the fourth ram's horn microstrip line 441.

[0044] like Figure 3As shown, the working center of the absorptive balanced filter power divider provided by the present invention is 2.0 GHz, the transmission zero is at 4.0 GHz, the measured differential mode return loss and isolation at the center frequency are better than 28 dB, the 15-dB differential mode return loss and isolation bandwidth is 493 MHz, and the differential mode insertion loss at the center frequency is 3.9 dB. The difference between the simulation and test insertion loss is 0.5 dB, which is mainly caused by factors such as connector loss and manufacturing accuracy. In addition, the transmission zero at 4.0 GHz on the right side of the passband provides excellent filtering characteristics. Figure 3 middle is the differential mode return loss; is the differential mode insertion loss; It is differential mode isolation.

[0045] like Figure 4 As shown, the absorptive balanced filter power divider provided by the present invention has a differential mode and common mode conversion return loss and isolation better than 30 dB at 2.0 GHz, and a 15-dB differential mode and common mode conversion bandwidth of 1274 MHz; Figure 4 middle Convert return loss for differential and common mode; Insertion loss for differential and common mode conversion; Isolation for differential and common mode conversion.

[0046] like Figure 5 As shown, the absorptive balanced filter power divider provided by the present invention has a common-mode return loss, insertion loss and isolation better than 26 dB at 2.0 GHz, and a 15-dB common-mode return loss, insertion loss and isolation bandwidth of 1291 MHz; Figure 5 middle is the common mode return loss; is the common mode insertion loss; For common mode isolation.

[0047] like Figure 6 As shown, the absorptive balanced filtering power divider provided by the present invention can maintain a stable phase characteristic at 2.0 GHz, and within the range of 0.5 GHz to 2.76 GHz, the phase difference of the reverse differential mode is always maintained within the range of 1°. Figure 6 The vertical axis is the phase difference of differential mode insertion loss.

[0048] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. An absorptive balanced filter power divider with arbitrary transmission zero point, constructed on a printed circuit board, characterized in that: include: A microstrip unit (1), a dielectric substrate (2) and a metal ground (3) are arranged in sequence from top to bottom; the microstrip unit is integrated with a first absorption network (51), a first low-pass filter unit (41), a second absorption network (52), a second low-pass filter unit (42), a third low-pass filter unit (43), a third absorption network (53) and a fourth low-pass filter unit (44); and the first absorption network (51), the first low-pass filter unit (41), the second absorption network (52), the second low-pass filter unit (42), the third low-pass filter unit (43), the third absorption network (53) and the fourth low-pass filter unit (44) are connected end to end in sequence to form a closed loop; The first absorption network (51) comprises: a first rectangular microstrip line (123), a first bent rectangular microstrip line (114), a second rectangular microstrip line (128) and a first branch line (111); the first rectangular microstrip line (123), the first bent rectangular microstrip line (114), the second rectangular microstrip line (128) and the first branch line (111) are connected end to end; the first rectangular microstrip line (123) is connected to the first input port (10) via a first feeder line (11); the second rectangular microstrip line (128) is connected to the first input port (10) via a second feeder line (14 ) is connected to a fourth input port (40); the upper end of the first bent rectangular microstrip line (114) is connected to the intersection of the first rectangular microstrip line (123) and the first feeder line (11), and the lower end of the first bent rectangular microstrip line (114) is connected to the intersection of the second rectangular microstrip line (128) and the second feeder line (14); the first absorption network (51) further includes a second bent rectangular microstrip line (115), and the second bent rectangular microstrip line (115) is arranged in parallel with the first bent rectangular microstrip line (114) to form an open-circuit coupled line structure.

2. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 1, characterized in that: The second absorption network (52) comprises: a third rectangular microstrip line (124), a second branch line (112), a fourth rectangular microstrip line (125) and a first concave microstrip line (118); the third rectangular microstrip line (124), the second branch line (112), the fourth rectangular microstrip line (125) and the first concave microstrip line (118) are connected end to end; the third rectangular microstrip line (124) is connected to the second input port (20) via a third feeder line (12); the fourth rectangular microstrip line (125) is connected to the second input port (20) via a fourth feeder line (118); 3) connected to a third input port (30); the left end of the first concave microstrip line (118) is connected to the intersection of the third rectangular microstrip line (124) and the third feeder line (12), and the right end of the first concave microstrip line (118) is connected to the intersection of the fourth rectangular microstrip line (125) and the fourth feeder line (13); the second absorption network (52) further includes a second concave microstrip line (117), and the second concave microstrip line (117) is arranged in parallel with the first concave microstrip line (118) to form an open-circuit coupled line structure.

3. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 2, characterized in that: The third absorption network (53) comprises: a fifth rectangular microstrip line (127), a first convex microstrip line (120), a sixth rectangular microstrip line (126) and a third branch line (113); the fifth rectangular microstrip line (127), the first convex microstrip line (120), the sixth rectangular microstrip line (126) and the third branch line (113) are connected end to end; the fifth rectangular microstrip line (127) is connected to the fifth input port (50) via a fifth feeder line (15); the sixth rectangular microstrip line (126) is connected to the fifth input port (50) via a sixth feeder line (15); 16) connected to the sixth input port (60); the left end of the first convex microstrip line (120) is connected to the intersection of the fifth rectangular microstrip line (127) and the fifth feeder (15), and the right end of the first convex microstrip line (120) is connected to the intersection of the sixth rectangular microstrip line (126) and the sixth feeder (16); the third absorption network (53) further includes: a second convex microstrip line (121), the second convex microstrip line (121) is arranged in parallel with the first convex microstrip line (120), and forms an open-circuit coupled line structure.

4. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 3, characterized in that: The line widths and line lengths of the first branch line (111), the second branch line (112) and the third branch line (113) are completely identical; the first bent rectangular microstrip line (114) and the second bent rectangular microstrip line (115), the first concave microstrip line (118) and the second concave microstrip line (117), and the first convex microstrip line (120) and the second convex microstrip line (121) form three groups of coupling lines, and the line width, line length and line spacing of each group of coupling lines are completely identical.

5. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 4, characterized in that: The first low-pass filtering unit (41) comprises: a seventh rectangular microstrip line (401), an eighth rectangular microstrip line (402), a ninth rectangular microstrip line (403), a first right-angled trapezoidal microstrip line (404), a second right-angled trapezoidal microstrip line (407), a tenth rectangular microstrip line (405), an eleventh rectangular microstrip line (406), a twelfth rectangular microstrip line (408), a thirteenth rectangular microstrip line (409), a first E-shaped microstrip line (410) and a first ram-shaped microstrip line (411); the first rectangular microstrip line (123), the seventh rectangular microstrip line (401), the eighth rectangular microstrip line (402), the ninth rectangular microstrip line (403) and the second branch line (112) are connected in sequence; the first low-pass filtering unit (41) comprises: a seventh rectangular microstrip line (401), an eighth rectangular microstrip line (402), the ninth rectangular microstrip line (403) and the second branch line (112) are connected in sequence; A right-angled trapezoidal microstrip line (404) and the second right-angled trapezoidal microstrip line (407) are respectively connected to the ends of the ninth rectangular microstrip line (403) and the seventh rectangular microstrip line (401); the twelfth rectangular microstrip line (408) is connected to the intersection of the second right-angled trapezoidal microstrip line (407) and the eleventh rectangular microstrip line (406); the thirteenth rectangular microstrip line (409) is connected to the intersection of the first right-angled trapezoidal microstrip line (404) and the tenth rectangular microstrip line (405); the midpoints of the first E-shaped microstrip line (410) and the first ram-shaped microstrip line (411) are respectively connected to the twelfth rectangular microstrip line (408) and the thirteenth rectangular microstrip line (409).

6. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 5, characterized in that: The second low-pass filtering unit (42) comprises: a fourteenth rectangular microstrip line (412), a fifteenth rectangular microstrip line (413), a sixteenth rectangular microstrip line (414), a third right-angled trapezoidal microstrip line (415), a fourth right-angled trapezoidal microstrip line (418), a seventeenth rectangular microstrip line (416), an eighteenth rectangular microstrip line (417), a nineteenth rectangular microstrip line (419), a twentieth rectangular microstrip line (422), a second E-shaped microstrip line (420) and a second ram-shaped microstrip line (421); the fourth rectangular microstrip line (125), the fourteenth rectangular microstrip line (412), the fifteenth rectangular microstrip line (413) and the sixteenth rectangular microstrip line (414) are connected in sequence, and the third right-angled trapezoidal microstrip line (415) and the fourth right-angled trapezoidal microstrip line (418) are connected in sequence. The fourth right-angled trapezoidal microstrip line (415) and the fourth right-angled trapezoidal microstrip line (418) are respectively connected to the ends of the sixteenth rectangular microstrip line (414) and the fourteenth rectangular microstrip line (412); the nineteenth rectangular microstrip line (419) is connected to the intersection of the fourth right-angled trapezoidal microstrip line (418) and the eighteenth rectangular microstrip line (417); the twentieth rectangular microstrip line (422) is connected to the intersection of the third right-angled trapezoidal microstrip line (415) and the seventeenth rectangular microstrip line (416); the midpoints of the second E-shaped microstrip line (420) and the second ram-shaped microstrip line (421) are respectively connected to the nineteenth rectangular microstrip line (419) and the twentieth rectangular microstrip line (422).

7. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 6, characterized in that: The third low-pass filtering unit (43) comprises: a twenty-first rectangular microstrip line (423), a twenty-second rectangular microstrip line (424), a twenty-third rectangular microstrip line (425), a fifth right-angled trapezoidal microstrip line (427), a sixth right-angled trapezoidal microstrip line (433), a twenty-fourth rectangular microstrip line (426), a twenty-fifth rectangular microstrip line (432), a twenty-sixth rectangular microstrip line (428), a twenty-seventh rectangular microstrip line (431), a third E-shaped microstrip line (429) and a third ram-shaped microstrip line (430); the sixth rectangular microstrip line (426), the twenty-third rectangular microstrip line (425), the twenty-second rectangular microstrip line (424), the twenty-first rectangular microstrip line (423) and the sixteenth rectangular microstrip line (414) are sequentially connected. The fifth right-angled trapezoidal microstrip line (427) and the sixth right-angled trapezoidal microstrip line (433) are respectively connected to the ends of the twenty-first rectangular microstrip line (423) and the twenty-third rectangular microstrip line (425); the twenty-sixth rectangular microstrip line (428) is connected to the intersection of the fifth right-angled trapezoidal microstrip line (427) and the twenty-fourth rectangular microstrip line (426); the twenty-seventh rectangular microstrip line (431) is connected to the intersection of the twenty-fifth rectangular microstrip line (432) and the sixth right-angled trapezoidal microstrip line (433); the midpoints of the third E-shaped microstrip line (429) and the third ram's horn microstrip line (430) are respectively connected to the twenty-sixth rectangular microstrip line (428) and the twenty-seventh rectangular microstrip line (431).

8. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 7, characterized in that: The fourth low-pass filtering unit (44) comprises: a twenty-eighth rectangular microstrip line (434), a twenty-ninth rectangular microstrip line (435), a thirtieth rectangular microstrip line (436), a seventh right-angled trapezoidal microstrip line (437), an eighth right-angled trapezoidal microstrip line (442), a thirty-first rectangular microstrip line (438), a thirty-second rectangular microstrip line (443), a thirty-third rectangular microstrip line (439), a thirty-fourth rectangular microstrip line (444), a fourth E-shaped microstrip line 440 and a fourth ram-shaped microstrip line (441); the thirty-fourth rectangular microstrip line (444) is connected to the intersection of the eighth right-angled trapezoidal microstrip line (442) and the thirty-second rectangular microstrip line (443), the thirty-third rectangular microstrip line (439) is connected to the intersection of the seventh right-angled trapezoidal microstrip line (437) and the thirty-third rectangular microstrip line (439); the second rectangular microstrip line (128), the thirtieth rectangular microstrip line ( The second rectangular microstrip line (436), the second rectangular microstrip line (435), the second rectangular microstrip line (434) and the third branch line (113) are connected in sequence, wherein the seventh right-angle trapezoidal microstrip line (437) and the eighth right-angle trapezoidal microstrip line (442) are connected to the ends of the second rectangular microstrip line (434) and the thirtieth rectangular microstrip line (436), respectively; the thirty-third rectangular microstrip line (439) is connected to the seventh right-angle trapezoidal microstrip line (437) and the eighth right-angle trapezoidal microstrip line (442) The trapezoidal microstrip line (437) and the thirty-first rectangular microstrip line (438) are connected at the intersection, and the thirty-fourth rectangular microstrip line (444) is connected to the intersection of the eighth right-angled trapezoidal microstrip line (442) and the thirty-second rectangular microstrip line (443); wherein the midpoints of the fourth E-shaped microstrip line (440) and the fourth ram's horn microstrip line (441) are respectively connected to the thirty-third rectangular microstrip line (439) and the thirty-fourth rectangular microstrip line (444).

9. The absorption balanced filter power divider with arbitrary transmission zero point according to claim 8, characterized in that: Also includes: A first absorption resistor (31), a second absorption resistor (32), a third absorption resistor (34) and an isolation resistor (33); one end of the first absorption resistor (31) is welded to a thirty-fifth rectangular microstrip line (116); the thirty-fifth rectangular microstrip line (116) is welded to the midpoint of the second bent rectangular microstrip line (115); the other end of the first absorption resistor (31) is welded to a first metal via (21) and then grounded; one end of the second absorption resistor (32) is welded to a thirty-sixth rectangular microstrip line (119); the thirty-sixth rectangular microstrip line (119) is welded to the midpoint of the second concave microstrip line (117); the other end of the second absorption resistor (32) is welded to the The first embodiment is a circuit diagram of a first convex microstrip line (121) and a second convex microstrip line (121) connected to a second metal via (22) and then grounded; one end of the third absorption resistor (34) is welded to a thirty-seventh rectangular microstrip line (122); the thirty-seventh rectangular microstrip line (122) is welded to the midpoint of the second convex microstrip line (121); the other end of the third absorption resistor (34) is welded to the third metal via (24) and then grounded; one end of the isolation resistor (33) is welded to a thirty-eighth rectangular microstrip line (129); the thirty-eighth rectangular microstrip line (129) is welded to the midpoint of the sixteenth rectangular microstrip line (414) and the twenty-first rectangular microstrip line (423); the other end of the isolation resistor (33) is welded to a fourth metal via (23) and then grounded.

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