Topological structure, wide dual-passband filter and communication equipment

Abstract

The embodiment of the utility model relates to the technical field of communication equipment, and particularly discloses a topological structure, a wide dual-passband filter and communication equipment, comprising a first parallel five-line and a second parallel five-line which are connected in sequence, and a first microstrip line and a sixth microstrip line which are symmetrically connected between the first parallel five-line and the second parallel five-line, the first micro-strip line is symmetrically connected with the second micro-strip line and the fourth micro-strip line, the second micro-strip line is sequentially connected with the third micro-strip line and the first short-circuit branch, the first short-circuit branch is grounded, the fourth micro-strip line is sequentially connected with the fifth micro-strip line and the second short-circuit branch, the second short-circuit branch is grounded, and the sixth micro-strip line is symmetrically connected with the seventh micro-strip line and the ninth micro-strip line. The seventh microstrip line is sequentially connected with the eighth microstrip line and a third short-circuit branch, the third short-circuit branch is grounded, the ninth microstrip line is sequentially connected with the tenth microstrip line and a fourth short-circuit branch, and the fourth short-circuit branch is grounded. Through the above mode, the embodiment of the utility model can obtain the wide dual-passband filter with small size and high selectivity based on the topological structure design.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of topological structures, and in particular to a topological structure, a wide dual-passband filter and a communication device. Background Art

[0002] With the rapid development of modern wireless communication technology, people's demand for broadband communication systems that can achieve high-speed data transmission is increasing, and it has become the focus of research by practitioners in related fields. Micro-bandwidth dual-passband filters with low cost, light weight, low profile and easy integration have attracted the attention of many scholars and engineers and have been deeply studied.

[0003] During the development of this invention, the inventors discovered that current dual-passband filters primarily employ parallel single-channel filters, insert transmission zeros within wide-passband filters, or employ short stubs of varying lengths within band-stop filters. However, dual-passband filters designed based on these three approaches often suffer from large size and poor selectivity, significantly limiting their use in modern wireless communication systems. Utility Model Content

[0004] The embodiments of the present invention provide a topology structure, a wide dual-passband filter and a communication device, which mainly solve the technical problem that the dual-passband filter is too large in size and has poor selectivity.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a topological structure including an input end, an output end, a first parallel five lines, a second parallel five lines, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, an eighth microstrip line, a ninth microstrip line, a tenth microstrip line, a first short-circuit branch, a second short-circuit branch, a third short-circuit branch and a fourth short-circuit branch; wherein, one end of the input end is connected to one end of the first parallel five lines, the other end of the first parallel five lines is respectively connected to one end of the second parallel five lines, one end of the first microstrip line and one end of the sixth microstrip line, the other end of the second parallel five lines is connected to the output end, the other end of the first microstrip line is respectively connected to one end of the second microstrip line and one end of the fourth microstrip line, the second microstrip line The other end of the fourth microstrip line is connected to one end of the fifth microstrip line, the other end of the fifth microstrip line is connected to one end of the second short-circuit branch, the other end of the second short-circuit branch is grounded, the other end of the sixth microstrip line is connected to one end of the seventh microstrip line and one end of the ninth microstrip line respectively, the other end of the seventh microstrip line is connected to the eighth microstrip line, the other end of the eighth microstrip line is connected to one end of the third short-circuit branch, the other end of the third short-circuit branch is grounded, the other end of the ninth microstrip line is connected to one end of the tenth microstrip line, the other end of the tenth microstrip line is connected to one end of the fourth short-circuit branch, and the other end of the fourth short-circuit branch is grounded.

[0006] Optionally, the first parallel five lines and the second parallel five lines are symmetrically arranged along a first direction; the first microstrip line and the sixth microstrip line are symmetrically arranged along a second direction, and the first direction and the second direction are perpendicular to each other.

[0007] Optionally, the first short-circuit branch and the third short-circuit branch, the third microstrip line and the eighth microstrip line, the second microstrip line and the seventh microstrip line are all symmetrically arranged about the first parallel five-line; the second short-circuit branch and the fourth short-circuit branch, the fifth microstrip line and the tenth microstrip line, the ninth microstrip line and the fourth microstrip line are all symmetrically arranged about the second parallel five-line.

[0008] Optionally, the first parallel five lines, the second parallel five lines, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch, the fourth short-circuit branch, the second microstrip line, the fourth microstrip line, the seventh microstrip line and the ninth microstrip line are all arranged in parallel.

[0009] Optionally, the first parallel five lines, the second parallel five lines, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch, the fourth short-circuit branch, the second microstrip line, the fourth microstrip line, the seventh microstrip line and the ninth microstrip line are all perpendicular to the first microstrip line, the third microstrip line, the fifth microstrip line, the sixth microstrip line, the eighth microstrip line and the tenth microstrip line.

[0010] Optionally, the characteristic impedance of the first microstrip line is equal to the characteristic impedance of the sixth microstrip line;

[0011] The characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fourth microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the seventh microstrip line, the characteristic impedance of the eighth microstrip line, the characteristic impedance of the ninth microstrip line, the characteristic impedance of the tenth microstrip line, the characteristic impedance of the first short-circuit stub, the characteristic impedance of the second short-circuit stub, the characteristic impedance of the third short-circuit stub, and the characteristic impedance of the fourth short-circuit stub are all equal; wherein the characteristic impedance of the first short-circuit stub is twice the characteristic impedance of the first microstrip line.

[0012] Optionally, the electrical length of the first parallel five lines is equal to the electrical length of the second parallel five lines; and both are equal to a quarter wavelength corresponding to the center frequency of the stop band between the two pass bands; the electrical length of the first microstrip line is equal to the electrical length of the sixth microstrip line; the electrical length of the second microstrip line, the electrical length of the fourth microstrip line, the electrical length of the seventh microstrip line and the electrical length of the ninth microstrip line are all equal; the electrical length of the third microstrip line, the electrical length of the fifth microstrip line, the electrical length of the eighth microstrip line and the electrical length of the tenth microstrip line are equal; the electrical length of the first short-circuit branch, the electrical length of the second short-circuit branch, the electrical length of the third short-circuit branch and the electrical length of the fourth short-circuit branch are equal.

[0013] Optionally, the electrical length of the first parallel five-wire line and the electrical length of the second parallel five-wire line are both one-quarter wavelength corresponding to the center frequency of the stop band between the two passbands; the sum of the electrical length of the first microstrip line, the electrical length of the second microstrip line, the electrical length of the third microstrip line, and the electrical length of the first short-circuit branch is one-half wavelength corresponding to the center frequency of the stop band between the two passbands.

[0014] In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a wide dual-passband filter obtained by the above topological structure design.

[0015] In order to solve the above technical problems, another technical solution adopted by the present invention is: providing a communication device, including the above wide dual-passband filter.

[0016] The beneficial effects of the embodiment of the utility model are as follows: different from the prior art, the embodiment of the utility model provides a topological structure including an input end, an output end, a first parallel five lines, a second parallel five lines, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, an eighth microstrip line, a ninth microstrip line, a tenth microstrip line, a first short-circuit branch, a second short-circuit branch, a third short-circuit branch and a fourth short-circuit branch; wherein, one end of the input end is connected to one end of the first parallel five lines, the other end of the first parallel five lines is respectively connected to one end of the second parallel five lines, one end of the first microstrip line and one end of the sixth microstrip line, the other end of the second parallel five lines is connected to the output end, the other end of the first microstrip line is respectively connected to one end of the second microstrip line and one end of the fourth microstrip line, the first microstrip line The other end of the second microstrip line is connected to the third microstrip line, the other end of the third microstrip line is connected to one end of the first short-circuit branch, the other end of the first short-circuit branch is grounded, the other end of the fourth microstrip line is connected to one end of the fifth microstrip line, the other end of the fifth microstrip line is connected to one end of the second short-circuit branch, the other end of the second short-circuit branch is grounded, the other end of the sixth microstrip line is respectively connected to one end of the seventh microstrip line and one end of the ninth microstrip line, the other end of the seventh microstrip line is connected to the eighth microstrip line, the other end of the eighth microstrip line is connected to one end of the third short-circuit branch, the other end of the third short-circuit branch is grounded, the other end of the ninth microstrip line is connected to one end of the tenth microstrip line, the other end of the tenth microstrip line is connected to one end of the fourth short-circuit branch, and the other end of the fourth short-circuit branch is grounded. The wide dual-passband filter designed based on the above topology has four transmission poles in its passband, which ensure the flatness of the passband, and five transmission zeros in its stopband, which ensure the high selectivity and high isolation of the filter, thereby ensuring the small size and high selectivity of the wide dual-passband filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0018] Figure 1 This is a schematic diagram of a topological structure provided by an embodiment of the present utility model;

[0019] Figure 2This is a schematic diagram of a layout of a wide dual-passband filter designed based on the above topological structure provided by an embodiment of the present invention;

[0020] Figure 3 This is a labeled diagram of the layout of a wide dual-passband filter designed based on the above topological structure provided by an embodiment of the present invention;

[0021] Figure 4 This is a diagram of S-parameter simulation results of a wide dual-passband filter obtained based on topological structure design provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this specification are for illustrative purposes only.

[0023] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this utility model belongs. The terms used in this specification and in the description of this utility model are only for the purpose of describing specific embodiments and are not intended to limit the utility model. The term "and / or" used in this specification includes any and all combinations of one or more of the relevant listed items.

[0024] See also Figure 1The topological structure 100 includes an input terminal 10, an output terminal 50, a first parallel five-wire 20, a second parallel five-wire 21, a first microstrip line 30, a second microstrip line 31, a third microstrip line 32, a fourth microstrip line 33, a fifth microstrip line 34, a sixth microstrip line 35, a seventh microstrip line 36, an eighth microstrip line 37, a ninth microstrip line 38, a tenth microstrip line 39, a first short-circuit branch 40, a second short-circuit branch 41, a third short-circuit branch 42 and a fourth short-circuit branch 43; wherein, one end of the input terminal 10 is connected to one end of the first parallel five-wire 20, the other end of the first parallel five-wire 20 is respectively connected to one end of the second parallel five-wire 21, one end of the first microstrip line 30 and one end of the sixth microstrip line 35, the other end of the second parallel five-wire 21 is connected to the output terminal 50, the other end of the first microstrip line 30 is respectively connected to one end of the second microstrip line 31 and one end of the fourth microstrip line 33, and the second The other end of the microstrip line 31 is connected to the third microstrip line 32, the other end of the third microstrip line 32 is connected to one end of the first short-circuit branch 40, the other end of the first short-circuit branch 40 is grounded, the other end of the fourth microstrip line 33 is connected to one end of the fifth microstrip line 34, the other end of the fifth microstrip line 34 is connected to one end of the second short-circuit branch 41, the other end of the second short-circuit branch 41 is grounded, the other end of the sixth microstrip line 35 is connected to one end of the seventh microstrip line 36 and one end of the ninth microstrip line 38 respectively, the other end of the seventh microstrip line 36 is connected to the eighth microstrip line 37, the other end of the eighth microstrip line 37 is connected to one end of the third short-circuit branch 42, the other end of the third short-circuit branch 42 is grounded, the other end of the ninth microstrip line 38 is connected to one end of the tenth microstrip line 39, the other end of the tenth microstrip line 39 is connected to one end of the fourth short-circuit branch 43, the other end of the fourth short-circuit branch 43 is grounded. The wide dual-passband filter designed based on the above structure has the characteristics of small size and high selectivity.

[0025] In some embodiments, the first parallel five lines 20 and the second parallel five lines 21 are symmetrically arranged along the first direction X; the first microstrip line 30 and the sixth microstrip line 35 are symmetrically arranged along the second direction Y, and the first direction X and the second direction Y are perpendicular to each other.

[0026] In some embodiments, the first short-circuit branch 40 and the third short-circuit branch 42, the third microstrip line 32 and the eighth microstrip line 37, the second microstrip line 31 and the seventh microstrip line 36 are all symmetrically arranged about the first parallel five-line 20; the second short-circuit branch 41 and the fourth short-circuit branch 43, the fifth microstrip line 34 and the tenth microstrip line 39, the ninth microstrip line 38 and the fourth microstrip line 33 are all symmetrically arranged about the second parallel five-line 21.

[0027] The first short-circuit branch 40 and the second short-circuit branch 41, the third microstrip line 32 and the fifth microstrip line 34, the second microstrip line 31 and the fourth microstrip line 33 are all symmetrically arranged about the first microstrip line 30; the third short-circuit branch 42 and the fourth short-circuit branch 43, the eighth microstrip line 37 and the tenth microstrip line 39, the ninth microstrip line 38 and the seventh microstrip line 36 are all symmetrically arranged about the sixth microstrip line 35.

[0028] In some embodiments, the first parallel five lines 20, the second parallel five lines 21, the first short-circuit branch 40, the second short-circuit branch 41, the third short-circuit branch 42, the fourth short-circuit branch 43, the second microstrip line 31, the fourth microstrip line 33, the seventh microstrip line 36 and the ninth microstrip line 38 are all arranged in parallel and along the first direction X.

[0029] In some embodiments, the first parallel five lines 20, the second parallel five lines 21, the first short-circuit branch 40, the second short-circuit branch 41, the third short-circuit branch 42, the fourth short-circuit branch 43, the second microstrip line 31, the fourth microstrip line 33, the seventh microstrip line 36 and the ninth microstrip line 38 are all perpendicular to the first microstrip line 30, the third microstrip line 32, the fifth microstrip line 34, the sixth microstrip line 35, the eighth microstrip line 37 and the tenth microstrip line 39.

[0030] Furthermore, the first parallel five-line 20 includes a first transmission line 201, a second transmission line 202, a third transmission line 203, a fourth transmission line 204, and a fifth transmission line 205, wherein the first transmission line 201, the second transmission line 202, the third transmission line 203, the fourth transmission line 204, and the fifth transmission line 205 are all parallel and equidistantly arranged, and the first transmission line 201, the third transmission line 203, and the fifth transmission line 205 are all connected to the input terminal 10, and the second transmission line 202 and the fourth transmission line 204 are all connected to the first microstrip line 30 and the sixth microstrip line 35; The second parallel five-line 21 includes a sixth transmission line 211, a seventh transmission line 212, an eighth transmission line 213, a ninth transmission line 214 and a tenth transmission line 215, wherein the sixth transmission line 211, the seventh transmission line 212, the eighth transmission line 213, the ninth transmission line 214 and the tenth transmission line 215 are all parallel and equidistantly arranged, and the sixth transmission line 211, the eighth transmission line 213 and the tenth transmission line 215 are all connected to the output end 50, and the seventh transmission line 212 and the ninth transmission line 214 are both connected to the first microstrip line 30 and the sixth microstrip line 35.

[0031] In some embodiments, the characteristic impedance of the first microstrip line 30 is equal to the characteristic impedance of the sixth microstrip line 35; the characteristic impedance of the second microstrip line 31, the characteristic impedance of the third microstrip line 32, the characteristic impedance of the fourth microstrip line 33, the characteristic impedance of the fifth microstrip line 34, the characteristic impedance of the seventh microstrip line 36, the characteristic impedance of the eighth microstrip line 37, the characteristic impedance of the ninth microstrip line 38, the characteristic impedance of the tenth microstrip line 39, the characteristic impedance of the first short-circuit stub 40, the characteristic impedance of the second short-circuit stub 41, the characteristic impedance of the third short-circuit stub 42, and the characteristic impedance of the fourth short-circuit stub 43 are all equal; wherein, the characteristic impedance of the first short-circuit stub 40 is twice the characteristic impedance of the first microstrip line 30.

[0032] In some embodiments, the electrical length of the first parallel five-line 20 is equal to the electrical length of the second parallel five-line 21; and both are equal to a quarter wavelength corresponding to the center frequency of the stopband between the two passbands; the electrical length of the first microstrip line 30 is equal to the electrical length of the sixth microstrip line 35; the electrical length of the second microstrip line 31, the electrical length of the fourth microstrip line 33, the electrical length of the seventh microstrip line 36 and the electrical length of the ninth microstrip line 38 are all equal; the electrical length of the third microstrip line 32, the electrical length of the fifth microstrip line 34, the electrical length of the eighth microstrip line 37 and the electrical length of the tenth microstrip line 39 are equal; the electrical length of the first short-circuit branch 40, the electrical length of the second short-circuit branch 41, the electrical length of the third short-circuit branch 42 and the electrical length of the fourth short-circuit branch 43 are equal.

[0033] Specifically, the electrical length of the first parallel five-wire line 20 and the electrical length of the second parallel five-wire line 21 are both one-quarter wavelength corresponding to the center frequency of the stop band between the two passbands; the sum of the electrical length of the first microstrip line 30, the electrical length of the second microstrip line 31, the electrical length of the third microstrip line 32, and the electrical length of the first short-circuit branch 40 is one-half wavelength corresponding to the center frequency of the stop band between the two passbands.

[0034] For the convenience of readers, please refer to Figure 2 and Figure 3 , provides a simulation example of a wide dual-passband filter designed using topology 100:

[0035] See also Figure 2 and Figure 3 The topology structure 100 is provided on a circuit board (not shown), and the size of the circuit board (not shown) is 29.0 mm*14.8 mm, the thickness is 0.813 mm, the dielectric constant is 3.38, and the wide dual-passband filter is provided on the circuit board. The size parameters of the topology structure 100 are: P =11.7mm,w P =0.1mm,s P=0.07mm, w1=2w2=2w3=2w4=1.8mm, l1=6.6mm, l2=8.8mm, l3=4.75mm, l4=5.4mm.

[0036] The simulation results of the wide dual-channel filter are shown in Figure 2. Figure 4 As shown. Figure 4 It can be seen that within the first passband, the impedance bandwidth with a reflection coefficient less than -10dB ranges from 1.405GHz to 2.623GHz, with a passband center frequency of 2.014GHz, an absolute passband bandwidth of 1.218GHz, and a relative passband bandwidth of 60.5%. Within the second passband, the impedance bandwidth with a reflection coefficient less than -10dB ranges from 5.217GHz to 6.679GHz, with a passband center frequency of 5.948GHz, an absolute passband bandwidth of 1.462GHz, and a relative passband bandwidth of 24.6%. This exhibits broadband characteristics. Furthermore, there are two transmission poles in the first passband, located at 1.502GHz and 2.308GHz, respectively; and two transmission poles in the second passband, located at 5.504GHz and 6.332GHz, respectively. This ensures the flatness of the passband of the wide dual-passband filter. There are five transmission zeros in the stopband, located at 0 GHz, 3.941 GHz, 4.299 GHz, 4.428 GHz, and 8.716 GHz. These five transmission zeros not only ensure the high selectivity of the wide dual-passband filter, but also ensure high isolation characteristics in the stopband.

[0037] Through the simulation example of the above topology structure 100 , it can be proved that the wide dual-passband filter designed based on the above topology structure 100 has the advantages of miniaturization and high selectivity.

[0038] The present invention also provides an embodiment of a wide dual-passband filter, which is designed by the above-mentioned topological structure 100. The specific structure and function of the above-mentioned topological structure 100 can be found in the above-mentioned embodiment, which will not be described in detail here.

[0039] The present invention also provides an embodiment of a communication device, including the wide dual-passband filter described above. The specific structure and function of the wide dual-passband filter can be found in the above embodiment, which will not be described in detail here.

[0040] It should be noted that the preferred embodiments of the present invention are given in the specification and drawings of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments do not serve as additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the description of the present invention; further, it is obvious to those skilled in the art that improvements or changes can be made based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A topological structure, characterized in that: include Input end, output end, first five parallel lines, second five parallel lines, first microstrip line, second microstrip line, third microstrip line, fourth microstrip line, fifth microstrip line, sixth microstrip line, seventh microstrip line, eighth microstrip line, ninth microstrip line, tenth microstrip line, first short-circuit branch, second short-circuit branch, third short-circuit branch and fourth short-circuit branch; Wherein, one end of the input end is connected to one end of the first parallel five lines, the other end of the first parallel five lines is respectively connected to one end of the second parallel five lines, one end of the first microstrip line and one end of the sixth microstrip line, the other end of the second parallel five lines is connected to the output end, the other end of the first microstrip line is respectively connected to one end of the second microstrip line and one end of the fourth microstrip line, the other end of the second microstrip line is connected to the third microstrip line, the other end of the third microstrip line is connected to one end of the first short-circuit branch, the other end of the first short-circuit branch is grounded, the other end of the fourth microstrip line is connected to the fifth microstrip line One end of the strip line is connected, the other end of the fifth microstrip line is connected to one end of the second short-circuit branch, the other end of the second short-circuit branch is grounded, the other end of the sixth microstrip line is connected to one end of the seventh microstrip line and one end of the ninth microstrip line respectively, the other end of the seventh microstrip line is connected to the eighth microstrip line, the other end of the eighth microstrip line is connected to one end of the third short-circuit branch, the other end of the third short-circuit branch is grounded, the other end of the ninth microstrip line is connected to one end of the tenth microstrip line, the other end of the tenth microstrip line is connected to one end of the fourth short-circuit branch, and the other end of the fourth short-circuit branch is grounded.

2. The topological structure according to claim 1, characterized in that: The first five parallel lines and the second five parallel lines are symmetrically arranged along a first direction; The first microstrip line and the sixth microstrip line are symmetrically arranged along a second direction, and the first direction is perpendicular to the second direction.

3. The topological structure according to claim 2, characterized in that: The first short-circuit branch and the third short-circuit branch, the third microstrip line and the eighth microstrip line, the second microstrip line and the seventh microstrip line are all symmetrically arranged about the first parallel five-line; The second short-circuit branch and the fourth short-circuit branch, the fifth microstrip line and the tenth microstrip line, the ninth microstrip line and the fourth microstrip line are all symmetrically arranged about the second parallel five-line.

4. The topological structure according to claim 3, characterized in that: The first parallel five lines, the second parallel five lines, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch, the fourth short-circuit branch, the second microstrip line, the fourth microstrip line, the seventh microstrip line and the ninth microstrip line are all arranged in parallel.

5. The topological structure according to claim 4, characterized in that: The first parallel five lines, the second parallel five lines, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch, the fourth short-circuit branch, the second microstrip line, the fourth microstrip line, the seventh microstrip line and the ninth microstrip line are all perpendicular to the first microstrip line, the third microstrip line, the fifth microstrip line, the sixth microstrip line, the eighth microstrip line and the tenth microstrip line.

6. The topological structure according to any one of claims 1 to 5, characterized in that: The characteristic impedance of the first microstrip line is equal to the characteristic impedance of the sixth microstrip line; the characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fourth microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the seventh microstrip line, the characteristic impedance of the eighth microstrip line, the characteristic impedance of the ninth microstrip line, the characteristic impedance of the tenth microstrip line, the characteristic impedance of the first short-circuit stub, the characteristic impedance of the second short-circuit stub, the characteristic impedance of the third short-circuit stub, and the characteristic impedance of the fourth short-circuit stub are all equal; The characteristic impedance of the first short-circuit branch is twice the characteristic impedance of the first microstrip line.

7. The topological structure according to any one of claims 1 to 5, characterized in that: The electrical length of the first parallel five lines is equal to the electrical length of the second parallel five lines; The electrical length of the first microstrip line is equal to the electrical length of the sixth microstrip line; the electrical length of the second microstrip line, the electrical length of the fourth microstrip line, the electrical length of the seventh microstrip line and the electrical length of the ninth microstrip line are all equal; The electrical length of the third microstrip line, the electrical length of the fifth microstrip line, the electrical length of the eighth microstrip line and the electrical length of the tenth microstrip line are equal; the electrical length of the first short-circuit branch, the electrical length of the second short-circuit branch, the electrical length of the third short-circuit branch and the electrical length of the fourth short-circuit branch are equal.

8. The topological structure according to claim 7, characterized in that: The electrical length of the first parallel five-line and the electrical length of the second parallel five-line are both a quarter wavelength corresponding to the center frequency of the stop band between the two pass bands; The sum of the electrical lengths of the first microstrip line, the second microstrip line, the third microstrip line, and the first short-circuit branch is half a wavelength corresponding to the center frequency of the stopband between the two passbands.

9. A wide dual-passband filter, characterized in that The topological structure is obtained by designing the topology according to any one of claims 1 to 8.

10. A communication device, characterized in that: Comprising the wide dual-passband filter as claimed in claim 9.

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