Topological structure and filter

Abstract

The embodiment of the invention relates to the technical field of filters, and discloses a topological structure and a filter. The topological structure comprises a parallel line, two parallel three lines, six microstrip lines and eight short-circuit branches. The first parallel three line and the second parallel three line are symmetrically arranged at the two ends of the first parallel line, the first end of the first microstrip line is connected with the first parallel line and the first parallel three line, and the first end of the second microstrip line and the first end of the third microstrip line are both connected with the second end of the first microstrip line; the first short-circuit branch knot and the second short-circuit branch knot are both connected with the second end of the second microstrip line, and the third short-circuit branch knot and the fourth short-circuit branch knot are both connected with the second end of the third microstrip line. The structures of the fourth microstrip line, the fifth microstrip line, the sixth microstrip line, the fifth short-circuit branch knot, the sixth short-circuit branch knot, the seventh short-circuit branch knot and the eighth short-circuit branch knot are similar. The internal structure of the topological structure is redesigned, so that the topological structure has the advantages of miniaturization, high selectivity, wide stop band and high isolation.

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 evolution of modern wireless communication technology, the research and development of broadband communication systems that can meet people's needs for high-speed data transmission is an inevitable trend of development. In this context, the research on miniaturization of bandpass filters, one of the key components of communication systems, has extremely high scientific and commercial value, attracting the attention of scholars and engineers. Unfortunately, however, the current miniaturized broadband filters often have the defects of poor selectivity, narrow stopband, and low isolation, which seriously affect their use in modern wireless communication systems. Summary of the invention

[0003] The main technical problem solved by the embodiments of the present application is to provide a topology structure and a filter that can at least solve some of the above-mentioned problems.

[0004] In order to solve the above technical problems, a technical solution adopted in an embodiment of the present application is: providing a topological structure for a filter, including a first parallel line, a first parallel three-line, a second parallel three-line, an input end and an output end, 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 first short-circuit branch, a second short-circuit branch, a third short-circuit branch, a fourth short-circuit branch, a fifth short-circuit branch, a sixth short-circuit branch, a seventh short-circuit branch and an eighth short-circuit branch. The first parallel three-line and the second parallel three-line are symmetrically arranged at the two ends of the first parallel line, the input end is connected to the end of the first parallel three-line, and the output end is connected to the end of the second parallel three-line. The first end of the first microstrip line is connected to the first parallel line and the first parallel three-line, the first end of the second microstrip line and the first end of the third microstrip line are both connected to the second end of the first microstrip line, the first short-circuit branch and the second short-circuit branch are both connected to the second end of the second microstrip line, and the third short-circuit branch and the fourth short-circuit branch are both connected to the second end of the third microstrip line. The first end of the fourth microstrip line is connected to the first parallel line and the second parallel three-line, the first end of the fifth microstrip line and the first end of the sixth microstrip line are both connected to the second end of the fourth microstrip line, the fifth short-circuit branch and the sixth short-circuit branch are both connected to the second end of the fifth microstrip line, and the seventh short-circuit branch and the eighth short-circuit branch are both connected to the second end of the sixth microstrip line.

[0005] In some embodiments, the first microstrip line and the fourth microstrip line are respectively located on both sides of the first parallel line.

[0006] In some embodiments, the second microstrip line and the third microstrip line are symmetrically arranged on both sides of the first microstrip line, the first short-circuit branch and the second short-circuit branch are symmetrically arranged on both sides of the second microstrip line, and the third short-circuit branch and the fourth short-circuit branch are symmetrically arranged on both sides of the third microstrip line.

[0007] In some embodiments, the first parallel line, the first three parallel lines, the second three parallel lines, the second microstrip line and the third microstrip line all extend along a first direction, the first microstrip line, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch and the fourth short-circuit branch all extend along a second direction, and the first direction is perpendicular to the second direction.

[0008] In some embodiments, the fifth microstrip line and the sixth microstrip line are symmetrically arranged on both sides of the fourth microstrip line, the fifth short-circuit branch and the sixth short-circuit branch are symmetrically arranged on both sides of the fifth microstrip line, and the seventh short-circuit branch and the eighth short-circuit branch are symmetrically arranged on both sides of the sixth microstrip line.

[0009] In some embodiments, the first parallel line, the first three parallel lines, the second three parallel lines, the fifth microstrip line and the sixth microstrip line all extend along a first direction, the fourth microstrip line, the fifth short-circuit branch, the sixth short-circuit branch, the seventh short-circuit branch and the eighth short-circuit branch all extend along a second direction, and the first direction is perpendicular to the second direction.

[0010] In some embodiments, the electrical length of the first parallel line, the electrical length of the first parallel three lines, and the electrical length of the second parallel three lines are equal, and are all equal to a quarter wavelength corresponding to the center frequency of the filter; the electrical length of the first microstrip line and the electrical length of the fourth microstrip line are equal; the electrical length of the second microstrip line, the electrical length of the third microstrip line, the electrical length of the fifth microstrip line, and the electrical length of the sixth 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, the electrical length of the fourth short-circuit branch, the electrical length of the fifth short-circuit branch, the electrical length of the sixth short-circuit branch, the electrical length of the seventh short-circuit branch, and the electrical length of the eighth short-circuit branch are equal.

[0011] In some embodiments, 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 greater than the electrical length of the first parallel line; the sum of the electrical length of the fourth microstrip line, the electrical length of the fifth microstrip line and the electrical length of the fifth short-circuit branch is greater than the electrical length of the first parallel line.

[0012] In some embodiments, the characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the sixth microstrip line, 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, the characteristic impedance of the fourth short-circuit branch, the characteristic impedance of the fifth short-circuit branch, the characteristic impedance of the sixth short-circuit branch, the characteristic impedance of the seventh short-circuit branch and the characteristic impedance of the eighth short-circuit branch are equal and are twice the characteristic impedance of the first microstrip line and the characteristic impedance of the fourth microstrip line.

[0013] In order to solve the above technical problem, another technical solution adopted in the embodiment of the present application is: to provide a filter, including a circuit board, and the circuit board is provided with the above topological structure.

[0014] The beneficial effects of the embodiments of the present application are as follows: Different from the prior art, the topological structure of the embodiments of the present application includes one parallel line, two parallel three lines, six microstrip lines and eight short-circuit branches. The first parallel three lines and the second parallel three lines are symmetrically arranged at the two ends of the first parallel line, the first end of the first microstrip line is connected to the first parallel line and the first parallel three lines, the first end of the second microstrip line and the first end of the third microstrip line are both connected to the second end of the first microstrip line, the first short-circuit branch and the second short-circuit branch are both connected to the second end of the second microstrip line, and the third short-circuit branch and the fourth short-circuit branch are both connected to the second end of the third microstrip line. The fourth microstrip line, the fifth microstrip line, the sixth microstrip line, the fifth short-circuit branch, the sixth short-circuit branch, the seventh short-circuit branch and the eighth short-circuit branch have similar structural arrangements. By redesigning the internal structure of the topological structure, it has the advantages of miniaturization and high selectivity, wide resistance band and high isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application, the following is a brief introduction to the drawings required for describing the specific embodiments. In all 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.

[0016] Figure 1 It is a schematic diagram of the topological structure of an embodiment of the present application.

[0017] Figure 2 This is the layout diagram of the topological structure of the embodiment of the present application on the circuit board.

[0018] Figure 3 It is an S parameter simulation diagram of the filter according to the embodiment of the present application. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] 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.

[0022] With the rapid evolution of modern wireless communication technology, the research and development of broadband communication systems that can meet people's needs for high-speed data transmission is an inevitable trend of development. In this context, the research on miniaturization of bandpass filters, one of the key components of communication systems, has extremely high scientific and commercial value, attracting the attention of scholars and engineers. Unfortunately, however, the current miniaturized broadband filters often have the defects of poor selectivity, narrow stopband, and low isolation, which seriously affect their use in modern wireless communication systems.

[0023] Based on this, an embodiment of the present application provides a topology structure for a filter, which has the advantages of miniaturization, high selectivity, wide resistance band and high isolation by redesigning the internal structure of the topology structure.

[0024] See also Figure 1The topological structure 100 of the embodiment of the present application includes a first parallel line 11, a first parallel three-line 12, a second parallel three-line 13, an input end 41 and an output end 42, a first microstrip line 21, a second microstrip line 22, a third microstrip line 23, a fourth microstrip line 24, a fifth microstrip line 25, a sixth microstrip line 26, a first short-circuit branch 31, a second short-circuit branch 32, a third short-circuit branch 33, a fourth short-circuit branch 34, a fifth short-circuit branch 35, a sixth short-circuit branch 36, a seventh short-circuit branch 37 and an eighth short-circuit branch 38. The first parallel three-line 12 and the second parallel three-line 13 are symmetrically arranged at both ends of the first parallel line 11, the input end 41 is connected to the end of the first parallel three-line 12, and the output end 42 is connected to the end of the second parallel three-line 13. The first end of the first microstrip line 21 is connected to the first parallel line 11 and the first parallel three-line 12, the first end of the second microstrip line 22 and the first end of the third microstrip line 23 are both connected to the second end of the first microstrip line 21, the first short-circuit branch 31 and the second short-circuit branch 32 are both connected to the second end of the second microstrip line 22, and the third short-circuit branch 33 and the fourth short-circuit branch 34 are both connected to the second end of the third microstrip line 23. The first end of the fourth microstrip line 24 is connected to the first parallel line 11 and the second parallel three-line 13, the first end of the fifth microstrip line 25 and the first end of the sixth microstrip line 26 are both connected to the second end of the fourth microstrip line 24, the fifth short-circuit branch 35 and the sixth short-circuit branch 36 are both connected to the second end of the fifth microstrip line 25, and the seventh short-circuit branch 37 and the eighth short-circuit branch 38 are both connected to the second end of the sixth microstrip line 26.

[0025] In some embodiments, see Figure 1 , the first microstrip line 21 and the fourth microstrip line 24 are respectively located on both sides of the first parallel line 11. Such a structure is conducive to having enough space for the layout of the second microstrip line 22 and the third microstrip line 23 connected to the first microstrip line 21, and is conducive to having enough space for the layout of the fifth microstrip line 25 and the sixth microstrip line 26 connected to the fourth microstrip line 24.

[0026] In some embodiments, see Figure 1 The second microstrip line 22 and the third microstrip line 23 are symmetrically arranged on both sides of the first microstrip line 21, the first short-circuit branch 31 and the second short-circuit branch 32 are symmetrically arranged on both sides of the second microstrip line 22, and the third short-circuit branch 33 and the fourth short-circuit branch 34 are symmetrically arranged on both sides of the third microstrip line 23.

[0027] In some embodiments, see Figure 1The first parallel line 11, the first parallel three lines 12, the second parallel three lines 13, the second microstrip line 22 and the third microstrip line 23 all extend along the first direction X, the first microstrip line 21, the first short-circuit branch 31, the second short-circuit branch 32, the third short-circuit branch 33 and the fourth short-circuit branch 34 all extend along the second direction Y, and the first direction X and the second direction Y are perpendicular.

[0028] In some embodiments, see Figure 1 The fifth microstrip line 25 and the sixth microstrip line 26 are symmetrically arranged on both sides of the fourth microstrip line 24, the fifth short-circuit branch 35 and the sixth short-circuit branch 36 are symmetrically arranged on both sides of the fifth microstrip line 25, and the seventh short-circuit branch 37 and the eighth short-circuit branch 38 are symmetrically arranged on both sides of the sixth microstrip line 26.

[0029] In some embodiments, see Figure 1 The first parallel line 11, the first parallel triple line 12, the second parallel triple line 13, the fifth microstrip line 25 and the sixth microstrip line 26 all extend along the first direction X, the fourth microstrip line 24, the fifth short-circuit branch 35, the sixth short-circuit branch 36, the seventh short-circuit branch 37 and the eighth short-circuit branch 38 all extend along the second direction Y, and the first direction X and the second direction Y are perpendicular.

[0030] In some embodiments, see Figure 1 and Figure 2 , the electrical length of the first parallel line 11, the electrical length of the first parallel three lines 12 and the electrical length of the second parallel three lines are equal, and are all equal to a quarter wavelength corresponding to the center frequency of the filter. The electrical length of the first microstrip line 21 is equal to the electrical length of the fourth microstrip line 24. The electrical length of the second microstrip line 22, the electrical length of the third microstrip line 23, the electrical length of the fifth microstrip line 25 and the electrical length of the sixth microstrip line 26 are equal. The electrical length of the first short-circuit branch 31, the electrical length of the second short-circuit branch 32, the electrical length of the third short-circuit branch 33, the electrical length of the fourth short-circuit branch 34, the electrical length of the fifth short-circuit branch 35, the electrical length of the sixth short-circuit branch 36, the electrical length of the seventh short-circuit branch 37 and the electrical length of the eighth short-circuit branch 38 are equal.

[0031] In some embodiments, see Figure 1 and Figure 2 The sum of the electrical lengths of the first microstrip line 21, the second microstrip line 22 and the first short-circuit stub 31 is greater than the electrical length of the first parallel line 11. The sum of the electrical lengths of the fourth microstrip line 24, the fifth microstrip line 25 and the fifth short-circuit stub 35 is greater than the electrical length of the first parallel line 11.

[0032] In some embodiments, the characteristic impedance of the second microstrip line 22, the characteristic impedance of the third microstrip line 23, the characteristic impedance of the fifth microstrip line 25, the characteristic impedance of the sixth microstrip line 26, the characteristic impedance of the first short-circuit branch 31, the characteristic impedance of the second short-circuit branch 32, the characteristic impedance of the third short-circuit branch 33, the characteristic impedance of the fourth short-circuit branch 34, the characteristic impedance of the fifth short-circuit branch 35, the characteristic impedance of the sixth short-circuit branch 36, the characteristic impedance of the seventh short-circuit branch 37 and the characteristic impedance of the eighth short-circuit branch 38 are equal and are twice the characteristic impedance of the first microstrip line 21 and the characteristic impedance of the fourth microstrip line 24.

[0033] The topological structure 100 of the embodiment of the present application includes one parallel line, two parallel three lines, six microstrip lines and eight short-circuit branches. The first parallel three lines 12 and the second parallel three lines 13 are symmetrically arranged at the two ends of the first parallel line 11, the first end of the first microstrip line 21 is connected to the first parallel line 11 and the first parallel three lines 12, the first end of the second microstrip line 22 and the first end of the third microstrip line 23 are both connected to the second end of the first microstrip line 21, the first short-circuit branch 31 and the second short-circuit branch 32 are both connected to the second end of the second microstrip line 22, and the third short-circuit branch 33 and the fourth short-circuit branch 34 are both connected to the second end of the third microstrip line 23. The fourth microstrip line 24, the fifth microstrip line 25, the sixth microstrip line 26, the fifth short-circuit branch 35, the sixth short-circuit branch 36, the seventh short-circuit branch 37 and the eighth short-circuit branch 38 have similar structural settings. By redesigning the internal structure of the topological structure 100, it has the advantages of miniaturization, high selectivity, wide resistance band and high isolation.

[0034] The present application further provides a filter embodiment, the filter includes a circuit board, and the circuit board is provided with a topological structure 100 in any of the above embodiments. For the specific structure and function of the topological structure 100, please refer to any of the above embodiments, which will not be repeated here.

[0035] The present invention uses a simulation example to illustrate the characteristics of this topology. The filter example 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. Its layout is shown in the following figure. Figure 2 The size of the entire layout is only 37.2mm*11.1mm, and the specific size of the filter is: T =10.2mm,s T =0.1mm,w T =0.2mm,l p =10.2mm,s p =0.1mm,w p =0.2mm, l1=4.1mm, w1=1.6mm, l2=6.4mm, w2=0.8mm, l3=2.6mm, w3=0.4mm.

[0036] The S parameter simulation results are as follows: Figure 3 As shown. Its passband range with reflection coefficient better than -10dB is 2.17GHz to 7.21GHz, the center frequency is 4.69GHz, the absolute bandwidth is 5.04GHz, and the relative bandwidth is 107.5%. In addition, there are eight transmission poles in the passband, located at 2.22GHz, 2.71GHz, 2.86GHz, 4.16GHz, 5.46GHz, 6.01GHz, 6.74GHz, and 7.14GHz, respectively. These eight transmission poles ensure the flatness of the passband. There are five transmission zeros in the stopband, located at 0GHz, 0.18GHz, 8.46GHz, 10.2GHz, and 10.64GHz, respectively. These five transmission zeros ensure the high selectivity, wide stopband, and high isolation of the filter.

[0037] 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 for a filter, characterized in that: include: A first parallel line, a first parallel three lines, a second parallel three lines, an input end and an output end, wherein the first parallel three lines and the second parallel three lines are symmetrically arranged at two ends of the first parallel line, the input end is connected to the end of the first parallel three lines, and the output end is connected to the end of the second parallel three lines; a first microstrip line, a second microstrip line, a third microstrip line, a first short-circuit branch, a second short-circuit branch, a third short-circuit branch and a fourth short-circuit branch, wherein the first end of the first microstrip line is connected to the first parallel line and the first three parallel lines, the first end of the second microstrip line and the first end of the third microstrip line are both connected to the second end of the first microstrip line, the first short-circuit branch and the second short-circuit branch are both connected to the second end of the second microstrip line, and the third short-circuit branch and the fourth short-circuit branch are both connected to the second end of the third microstrip line; The fourth microstrip line, the fifth microstrip line, the sixth microstrip line, the fifth short-circuit branch, the sixth short-circuit branch, the seventh short-circuit branch and the eighth short-circuit branch, the first end of the fourth microstrip line is connected to the first parallel line and the second parallel three lines, the first end of the fifth microstrip line and the first end of the sixth microstrip line are both connected to the second end of the fourth microstrip line, the fifth short-circuit branch and the sixth short-circuit branch are both connected to the second end of the fifth microstrip line, and the seventh short-circuit branch and the eighth short-circuit branch are both connected to the second end of the sixth microstrip line.

2. The topological structure according to claim 1, characterized in that: The first microstrip line and the fourth microstrip line are respectively located on two sides of the first parallel line.

3. The topological structure according to claim 1, characterized in that: The second microstrip line and the third microstrip line are symmetrically arranged on both sides of the first microstrip line, the first short-circuit branch and the second short-circuit branch are symmetrically arranged on both sides of the second microstrip line, and the third short-circuit branch and the fourth short-circuit branch are symmetrically arranged on both sides of the third microstrip line.

4. The topological structure according to claim 3, characterized in that: The first parallel line, the first parallel three lines, the second parallel three lines, the second microstrip line and the third microstrip line all extend along a first direction, the first microstrip line, the first short-circuit branch, the second short-circuit branch, the third short-circuit branch and the fourth short-circuit branch all extend along a second direction, and the first direction is perpendicular to the second direction.

5. The topological structure according to any one of claims 1 to 4, characterized in that: The fifth microstrip line and the sixth microstrip line are symmetrically arranged on both sides of the fourth microstrip line, the fifth short-circuit branch and the sixth short-circuit branch are symmetrically arranged on both sides of the fifth microstrip line, and the seventh short-circuit branch and the eighth short-circuit branch are symmetrically arranged on both sides of the sixth microstrip line.

6. The topological structure according to claim 5, characterized in that: The first parallel line, the first three parallel lines, the second three parallel lines, the fifth microstrip line and the sixth microstrip line all extend along a first direction, the fourth microstrip line, the fifth short-circuit branch, the sixth short-circuit branch, the seventh short-circuit branch and the eighth short-circuit branch all extend along a second direction, and the first direction is perpendicular to the second direction.

7. The topological structure according to claim 5, characterized in that: The electrical length of the first 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 filter; The electrical length of the first microstrip line is equal to the electrical length of the fourth microstrip line; The electrical length of the second microstrip line, the electrical length of the third microstrip line, the electrical length of the fifth microstrip line and the electrical length of the sixth 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, the electrical length of the fourth short-circuit branch, the electrical length of the fifth short-circuit branch, the electrical length of the sixth short-circuit branch, the electrical length of the seventh short-circuit branch and the electrical length of the eighth short-circuit branch are equal.

8. The topological structure according to claim 7, 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 greater than the electrical length of the first parallel line; The sum of the electrical length of the fourth microstrip line, the electrical length of the fifth microstrip line and the electrical length of the fifth short-circuit branch is greater than the electrical length of the first parallel line.

9. The topological structure according to claim 5, characterized in that: The characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the sixth microstrip line, 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, the characteristic impedance of the fourth short-circuit branch, the characteristic impedance of the fifth short-circuit branch, the characteristic impedance of the sixth short-circuit branch, the characteristic impedance of the seventh short-circuit branch and the characteristic impedance of the eighth short-circuit branch are equal, and are all twice the characteristic impedance of the first microstrip line and the characteristic impedance of the fourth microstrip line.

10. A filter, characterized in that: It comprises a circuit board, wherein the circuit board is provided with a topological structure as claimed in any one of claims 1-9.

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