Topological structure, filter and communication equipment

Abstract

The embodiment of the invention relates to the technical field of filters, and discloses a topological structure, a filter and communication equipment, and the topological structure comprises an input end, a first parallel three-line, a parallel line, a second parallel three-line, a first transmission line assembly, a second transmission line assembly, and an output port. The first three parallel lines and the second three parallel lines are located on the two sides of the parallel line and are located on the same straight line with the parallel line; the first transmission line assembly and the second transmission line assembly are symmetrically distributed on the two sides of the parallel line. And the input end, the first parallel three-line, the parallel line, the second parallel three-line and the output port are sequentially cascaded on the same straight line. By means of the mode, compared with other high-order ultra-wideband filters, the high-order ultra-wideband filter has the advantages of being good in selectivity, compact in structure and small in size.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of filter technology, and in particular to a topology structure and a filter. Background Art

[0002] With the rapid development of modern wireless communication technology, high-speed data transmission and precise positioning of targets have become key technical requirements for the Internet of Everything. In this context, UWB (ultra-wideband) positioning technology has emerged and gradually entered daily production and life. High-order ultra-wideband filters are one of the key components of UWB positioning systems, which can improve positioning accuracy and data transmission speed.

[0003] In the process of implementing the embodiments of the present application, the inventors found that: currently, high-order ultra-wideband filters require more cascaded resonant units to achieve better selectivity. Each additional order requires an increase in the corresponding transmission line structure, which leads to an increase in size. In conventional designs, the units at each level are mostly arranged in series or parallel. Therefore, traditional high-order ultra-wideband filters generally have the problem of being too large in size, which seriously affects their practical application in modern miniaturized wireless communication systems. Summary of the invention

[0004] The main technical problem solved by the embodiments of the present application is to provide a topological structure that achieves an ultra-wide operating bandwidth of 3.168-10.62 GHz, 7 transmission poles in the passband to ensure good insertion loss flatness, and 5 transmission zeros in the stopband to provide excellent selectivity and isolation. Compared with other high-order ultra-wideband filters, it has the advantages of good selectivity, compact structure and miniaturization.

[0005] In order to solve the above technical problems, a technical solution adopted in an embodiment of the present application is: providing a topological structure, including an input end, a first parallel three wires, a parallel line, a second parallel three wires, a first transmission line component, a second transmission line component and an output port, the first parallel three wires and the second parallel three wires are located on both sides of the parallel lines and are on the same straight line with the parallel lines; the first transmission line component and the second transmission line component are symmetrically distributed on both sides of the parallel lines; the input end, the first parallel three wires, the parallel line, the second parallel three wires and the output port are cascaded in sequence on the same straight line.

[0006] Optionally, the first transmission line includes 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 and an eighth microstrip line; the first parallel three lines and the second parallel three lines, the first microstrip line and the fifth microstrip line, the third microstrip line and the seventh microstrip line are all arranged symmetrically about the parallel lines.

[0007] Optionally, the first microstrip line and the third microstrip line, the fifth microstrip line and the seventh microstrip line are arranged symmetrically up and down about the straight line where the parallel line is located.

[0008] Optionally, the second transmission line component includes a first short-circuit branch, a second short-circuit branch, a third short-circuit branch and a fourth short-circuit branch; the parallel lines, the first three parallel lines, the second three parallel lines, the second microstrip line, the fourth microstrip line, the sixth microstrip line and the eighth microstrip line are parallel to each other and are perpendicular to the first microstrip line, the third microstrip line, the fifth microstrip line, the seventh microstrip line, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch and the fourth short-circuit branch.

[0009] Optionally, the electrical length of the parallel line, the electrical length of the first three parallel lines and the electrical length of the second three parallel lines are equal, and are all equal to a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

[0010] Optionally, the sum of the electrical length of the first microstrip line, the electrical length of the second microstrip line, and the electrical length of the first short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter; the sum of the electrical length of the third microstrip line, the electrical length of the fourth microstrip line, and the electrical length of the second short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

[0011] Optionally, the sum of the electrical length of the fifth microstrip line, the electrical length of the sixth microstrip line, and the electrical length of the third short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter; the sum of the electrical length of the seventh microstrip line, the electrical length of the eighth microstrip line, and the electrical length of the fourth short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

[0012] Optionally, the characteristic impedance of the first transmission line component is equal to the characteristic impedance of the second transmission line component.

[0013] In order to solve the above technical problems, another technical solution adopted in the embodiment of the present application is: providing a filter, including any one of the above topological structures.

[0014] In order to solve the above technical problem, another technical solution adopted in the embodiment of the present application is: providing a communication device, including the above filter.

[0015] The embodiment of the present application provides a topological structure, including an input end, a first parallel three-wire, a parallel line, a second parallel three-wire, a first transmission line component, a second transmission line component and an output port, wherein the first parallel three-wire and the second parallel three-wire are located on both sides of the parallel line and are on the same straight line with the parallel line; the first transmission line component and the second transmission line component are symmetrically distributed on both sides of the parallel line; the input end, the first parallel three-wire, the parallel line, the second parallel three-wire and the output port are cascaded in sequence on the same straight line, and a compact structure is achieved by setting a composite structure of parallel lines, parallel three-wires, the first transmission component and the second transmission component, and a symmetrical layout method. While effectively saving plane space, an ultra-wide operating bandwidth of 3.168-10.62 GHz and 7 transmission poles in the passband are achieved, ensuring good insertion loss flatness, and 5 transmission zeros in the stopband provide excellent selectivity and isolation. Compared with other high-order ultra-wideband filters, it has the advantages of good selectivity, compact structure and miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0017] Figure 1 is a schematic diagram of the topological structure of an embodiment of the present application;

[0018] Figure 2 It is a layout diagram of a filter designed based on a topological structure according to an embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of the filter S parameter simulation results. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present application, the present application 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 another 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 another element or there can be one or more centered elements therebetween. The orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0022] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0023] See also Figure 1 The topological structure 100 includes an input end 10, a first parallel three-wire 20, a parallel line 30, a second parallel three-wire 40, a first transmission line component 50, a second transmission line component 60 and an output port 70, wherein the first parallel three-wire 20 and the second parallel three-wire 40 are located on both sides of the parallel line 30 and are on the same straight line with the parallel line 30; the first transmission line component 50 and the second transmission line component 60 are symmetrically distributed on both sides of the parallel line 30; the input end 10, the first parallel three-wire 20, the parallel line 30, the second parallel three-wire 40 and the output port 70 are cascaded in sequence on the same straight line. Through the above arrangement, a symmetrical topological structure 100 is formed, which realizes an ultra-wide operating bandwidth of 3.168-10.62 GHz, 7 transmission poles in the passband ensure good insertion loss flatness, and 5 transmission zeros in the stopband provide excellent selectivity and isolation, and constitutes the filter in the present application.

[0024] For details, please continue to refer to Figure 1, the first transmission line component 50 includes a first microstrip line 501, a second microstrip line 502, a third microstrip line 503, a fourth microstrip line 504, a fifth microstrip line 505, a sixth microstrip line 506, a seventh microstrip line 507 and an eighth microstrip line 508, the first parallel three lines 20 and the second parallel three lines 40, the first microstrip line 501 and the fifth microstrip line 505, the third microstrip line 503 and the seventh microstrip line 507 are all arranged symmetrically about the parallel line 30, and the symmetrical circuit structure can effectively offset the parasitic effects in the circuit, reduce the nonlinear distortion of the circuit, and improve the linearity of the filter. The symmetrical structure can also reduce the asymmetric loss in the circuit and improve the transmission efficiency of the filter. In some embodiments, the symmetrical structure can also enhance the filtering characteristics of the filter, such as improving the passband flatness, the stopband suppression capability, etc. By adjusting the parameters of the symmetrical structure, filters with different filtering characteristics can be flexibly designed to meet different application requirements.

[0025] Furthermore, the first microstrip line 501 and the third microstrip line 503, the fifth microstrip line 505 and the seventh microstrip line 507 are symmetrically arranged up and down about the straight line where the parallel line 30 is located. Through the above arrangement, the electromagnetic field distribution in the circuit can be balanced, the asymmetric loss in the circuit can be reduced, the transmission efficiency of the filter can be improved, and the parasitic effects in the circuit, such as parasitic capacitance, parasitic inductance, etc., can be effectively suppressed to improve the performance of the filter.

[0026] For details, please continue to refer to Figure 1 The second transmission line component 60 includes a first short-circuit branch 601, a second short-circuit branch 602, a third short-circuit branch 603 and a fourth short-circuit branch 604, the parallel line 30, the first parallel three lines 20, the second parallel three lines 40, the second microstrip line 502, the fourth microstrip line 504, the sixth microstrip line 506 and the eighth microstrip line 508 are parallel to each other and are perpendicular to the first microstrip line 501, the third microstrip line 503, the fifth microstrip line 505, the seventh microstrip line 507, the first microstrip line 508, the second microstrip line 509, the first microstrip line 501, the third microstrip line 503, the fifth microstrip line 505, the seventh microstrip line 507, the first microstrip line 508, the second microstrip line 502, the fourth microstrip line 504, the sixth microstrip line 506 and the eighth microstrip line 508. The first short-circuit branch 601, the second short-circuit branch 602, the third short-circuit branch 603, and the fourth short-circuit branch 604, the parallel arranged transmission lines can effectively guide the electromagnetic field so that it propagates along the direction of the transmission line, reduce the scattering and loss of the electromagnetic field in space, and can constitute different circuit elements, such as resonators, transmission lines, couplers, etc., to realize the filtering function of the filter; further, the vertically arranged transmission lines can effectively separate different circuit areas, prevent mutual interference between electromagnetic fields, and improve the isolation of the filter.

[0027] In an embodiment of the present invention, the electrical length of the parallel line 30, the electrical length of the first parallel three lines 20 and the electrical length of the second parallel three lines 40 are equal, and are all equal to a quarter wavelength corresponding to the center frequency of the ultra-wideband filter. When the electrical length of the transmission line is equal to a quarter wavelength of a specific frequency, the transmission line will exhibit a resonant characteristic, that is, at this frequency, the input impedance and output impedance of the transmission line are both pure resistors and are equal in size. Using this resonant characteristic, a resonator can be constructed to achieve the filtering function of the filter in the present application, and the electrical length matching between the parallel line 30, the parallel three lines and the plurality of microstrip lines can ensure that the filter has good matching characteristics at the center frequency, that is, the input impedance and output impedance of the filter match the impedance of the external circuit, thereby improving the transmission efficiency of the filter.

[0028] In an embodiment of the present application, the sum of the electrical length of the fifth microstrip line 505, the electrical length of the sixth microstrip line 506, and the electrical length of the third short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter; the sum of the electrical length of the seventh microstrip line 507, the electrical length of the eighth microstrip line 508, and the electrical length of the fourth short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter. Furthermore, through the above-mentioned settings, a resonator can be constructed, and its resonant characteristics can be used to achieve a filtering function.

[0029] In the embodiment of the present application, the characteristic impedance of the first transmission line component 50 is equal to the characteristic impedance of the second transmission line component 60. Specifically, the characteristic impedance of the first microstrip line 501, the characteristic impedance of the second microstrip line 502, the characteristic impedance of the third microstrip line 503, the characteristic impedance of the fourth microstrip line 504, the characteristic impedance of the fifth microstrip line 505, the characteristic impedance of the sixth microstrip line 506, the characteristic impedance of the seventh microstrip line 507, the characteristic impedance of the eighth microstrip line 508, the characteristic impedance of the first short-circuit branch, the characteristic impedance of the second short-circuit branch, the characteristic impedance of the third short-circuit branch, and the characteristic impedance of the fourth short-circuit branch are equal.

[0030] Based on the topological structure 100 in the present application, the present application also provides a filter embodiment, wherein the filter embodiment is designed on a circuit board with a dielectric constant of 3.38, a dielectric loss of 0.0022, and a thickness of 0.813 mm. The layout diagram thereof is as follows: Figure 2 As shown, T =7.0mm,s T =0.1mm,w T =0.2mm,l P =7.0mm,s P =0.1mm,w p=0.1mm, l1=2.95mm, l2=3.4mm, l3=1.4mm, W1=0.4mm. The S parameter simulation results of the filter are as follows Figure 3 As shown. Its passband range with reflection coefficient better than -10dB is 3.168GHz to 10.62GHz, the center frequency is 6.894GHz, the absolute bandwidth is 7.452GHz, and the relative bandwidth is 108.1%. In addition, there are seven transmission poles in the passband, located at 3.372, 4.605, 6.721, 7.063, 8.95, 0.178, and 10.52GHz, respectively. These seven transmission poles ensure the flatness of the passband insertion loss. There are five transmission zeros in the stopband, located at 0, 0.587, 11.626, 14.425, and 15.152GHz, respectively. These five transmission zeros ensure high selectivity, wide stopband, and high isolation.

[0031] The embodiment of the present application provides a topological structure 100, including an input terminal 10, a first parallel three wires 20, a parallel wire 30, a second parallel three wires 40, a first transmission line component 50, a second transmission line component 60, and an output port 70, wherein the first parallel three wires 20 and the second parallel three wires 40 are located on both sides of the parallel wire 30 and are on the same straight line as the parallel wire 30; the first transmission line component 50 and the second transmission line component 60 are symmetrically distributed on both sides of the parallel wire 30; the input terminal 10, the first parallel three wires 20, the parallel wires 30, the second parallel three wires 40, and the output port 70 The outlet ports 70 are cascaded in sequence on the same straight line. By setting a composite structure of parallel lines 30, three parallel lines, a first transmission component and a second transmission component, and a symmetrical layout, a compact structure is achieved. While effectively saving the plane space, an ultra-wide operating bandwidth of 3.168-10.62 GHz and 7 transmission poles in the passband are achieved, ensuring good insertion loss flatness. The 5 transmission zeros in the stopband provide excellent selectivity and isolation. Compared with other high-order ultra-wideband filters, it has the advantages of good selectivity, compact structure and miniaturization.

[0032] The present application also provides a communication device embodiment, wherein the communication device includes the above-mentioned filter. The specific structure and function of the filter can be referred to the above-mentioned embodiment, which will not be repeated here.

[0033] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A topological structure, characterized in that: include: Input terminal; The first parallel line; parallel lines; A second parallel three lines, wherein the first parallel three lines and the second parallel three lines are located on both sides of the parallel line and are in the same straight line as the parallel line; a first transmission line assembly; a second transmission line component, wherein the first transmission line component and the second transmission line component are symmetrically distributed on both sides of the parallel line; The output port, the input port, the first three parallel lines, the parallel line, the second three parallel lines and the output port are cascaded in sequence on the same straight line.

2. The topological structure according to claim 1, characterized in that: The first transmission line includes 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 and an eighth microstrip line; The first parallel three lines and the second parallel three lines, the first microstrip line and the fifth microstrip line, the third microstrip line and the seventh microstrip line are all arranged symmetrically about the parallel lines.

3. The topological structure according to claim 2, characterized in that: The first microstrip line and the third microstrip line, the fifth microstrip line and the seventh microstrip line are vertically and symmetrically arranged with respect to the straight line where the parallel line is located.

4. The topological structure according to claim 2, characterized in that: The second transmission line assembly includes a first short-circuit branch, a second short-circuit branch, a third short-circuit branch and a fourth short-circuit branch; The parallel lines, the first three parallel lines, the second three parallel lines, the second microstrip line, the fourth microstrip line, the sixth microstrip line and the eighth microstrip line are parallel to each other, and are perpendicular to the first microstrip line, the third microstrip line, the fifth microstrip line, the seventh microstrip line, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch and the fourth short-circuit branch.

5. The topological structure according to claim 1, characterized in that: The electrical length of the parallel lines, the electrical length of the first three parallel lines, and the electrical length of the second three parallel lines are equal, and are all equal to a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

6. The topological structure according to claim 4, characterized in that: The sum of the electrical length of the first microstrip line, the electrical length of the second microstrip line, and the electrical length of the first short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter; the sum of the electrical length of the third microstrip line, the electrical length of the fourth microstrip line, and the electrical length of the second short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

7. The topological structure according to claim 4, characterized in that: The sum of the electrical length of the fifth microstrip line, the electrical length of the sixth microstrip line, and the electrical length of the third short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter; the sum of the electrical length of the seventh microstrip line, the electrical length of the eighth microstrip line, and the electrical length of the fourth short-circuit branch is a quarter wavelength corresponding to the center frequency of the ultra-wideband filter.

8. The topological structure according to claim 1, characterized in that: The characteristic impedance of the first transmission line component is equal to the characteristic impedance of the second transmission line component.

9. A filter, characterized in that: Comprising a topological structure as described in any one of claims 1-9.

10. A topological structure, characterized in that: Comprising a topological structure as described in any one of claims 1-9.

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