Topological structure of high-selectivity ultra-wideband filter and filter

Abstract

The utility model discloses a topological structure of a high-selectivity ultra-wideband filter, which comprises a first microstrip line arranged along a first direction, a first end of the first microstrip line is symmetrically connected with a first open-circuit branch knot and a second open-circuit branch knot, a second end of the first microstrip line is symmetrically connected with a first parallel three-line and a second parallel three-line, the other end of the first parallel three-wire is connected with an input end, and the other end of the second parallel three-wire is connected with an output end; the first open-circuit branch knot, the second open-circuit branch knot, the first three parallel lines and the second three parallel lines are arranged along a second direction, the second direction is perpendicular to the first direction, and the first open-circuit branch knot and the second open-circuit branch knot are symmetrical about the first microstrip line; the first three parallel lines and the second three parallel lines are symmetrical about the first microstrip line. The ultra-wideband filter overcomes the defect that an existing ultra-wideband filter is not high in selectivity.

Description

Technical Field

[0001] The utility model relates to the technical field of filters, in particular to a topological structure of a highly selective ultra-wideband filter and a filter. Background Art

[0002] With the rapid development of modern 5G communication technology, ultra-wideband systems with high data transmission rate, strong anti-interference ability and low power consumption have attracted more and more attention from engineers and scholars. As one of its key components, ultra-wideband filters have become one of the focuses of research. However, most of the existing ultra-wideband filters have the defect of low selectivity and cannot efficiently utilize spectrum resources, which greatly limits their use in modern wireless communication systems. Utility Model Content

[0003] The main purpose of the utility model is to provide a topological structure of a highly selective ultra-wideband filter and a filter, aiming to solve the defect of low selectivity of the existing ultra-wideband filter.

[0004] To achieve the above-mentioned object, the utility model proposes a topological structure of a highly selective ultra-wideband filter, comprising a first microstrip line arranged along a first direction, a first end of the first microstrip line symmetrically connected to a first open-circuit branch and a second open-circuit branch, a second end of the first microstrip line symmetrically connected to a first parallel three-wire and a second parallel three-wire, the other end of the first parallel three-wire is connected to an input end, and the other end of the second parallel three-wire is connected to an output end;

[0005] The first open branch, the second open branch, the first three parallel lines and the second three parallel lines are all arranged along a second direction, the second direction is perpendicular to the first direction, and the first open branch and the second open branch are symmetrical about the first microstrip line, and the first three parallel lines and the second three parallel lines are symmetrical about the first microstrip line.

[0006] Optionally, the first parallel three lines and the second parallel three lines each include a first transmission line, a second transmission line and a third transmission line that are parallel to each other, the second transmission line is located between the first transmission line and the third transmission line, the second transmission line is used to connect to the input end or the output end, and the first transmission line and the third transmission line are respectively used to connect to the first microstrip line.

[0007] Optionally, the electrical lengths of the first microstrip line, the first open-circuit branch, the second open-circuit branch, the first parallel three-line, and the second parallel three-line are all one-quarter wavelength corresponding to the center frequency of the filter.

[0008] To achieve the above object, the utility model also proposes a filter, including a filter designed with any of the above-mentioned topological structures.

[0009] Optionally, the filter further includes a circuit board, the circuit board has a dielectric loss of 0.0022, a thickness of 0.813 mm, and a size of 19.0 mm*10.0 mm.

[0010] Optionally, the line width of the transmission line in the first parallel three lines and the second parallel three lines is set to w p =0.4mm, line spacing is set to s p =0.1mm, line length is set to l p =6.9mm.

[0011] Optionally, the length of the first microstrip line is set to l 1 =7.8mm, width is set to w 1 =1.2mm; the length of the first open branch and the second open branch is set to l 2 =7.9mm, width is set to w 2 =0.4mm.

[0012] The beneficial effects of the utility model are: improving the topological structure of the existing ultra-wideband filter, including a first microstrip line arranged along a first direction, a first end of the first microstrip line symmetrically connected with a first open branch and a second open branch, a second end of the first microstrip line symmetrically connected with a first parallel three-wire and a second parallel three-wire, the other end of the first parallel three-wire is connected with an input end, and the other end of the second parallel three-wire is connected with an output end; the first open branch, the second open branch, the first parallel three-wire and the second parallel three-wire are all arranged along a second direction, the second direction is perpendicular to the first direction, and the first open branch and the second open branch are symmetrical about the first microstrip line, and the first parallel three-wire and the second parallel three-wire are symmetrical about the first microstrip line. The ultra-wideband filter designed based on the topological structure of the utility model has the advantage of high selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0014] Figure 1 This is a schematic diagram of the topological structure of the filter of the utility model;

[0015] Figure 2 This is a layout diagram of the filter of the utility model;

[0016] Figure 3The S parameter simulation results of the utility model filter are different with different s P Graph of changes in

[0017] Figure 4 The S parameter simulation results of the utility model filter are as follows: P Graph of changes in

[0018] Figure 5 The S parameter simulation results of the utility model filter are as follows: 1 Graph of changes in

[0019] Figure 6 The S parameter simulation results of the utility model filter are as follows: 2 Graph of changes in

[0020] Figure 7 This is a schematic diagram of the S parameter simulation results of the utility model filter;

[0021] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0025] An embodiment of the present invention provides a topological structure of a highly selective ultra-wideband filter, referring to Figure 1 , comprising a first microstrip line arranged along a first direction, a first end of the first microstrip line being symmetrically connected to a first open branch node and a second open branch node, a second end of the first microstrip line being symmetrically connected to a first parallel three-wire and a second parallel three-wire, the other end of the first parallel three-wire being connected to an input end, and the other end of the second parallel three-wire being connected to an output end;

[0026] The first open branch, the second open branch, the first three parallel lines and the second three parallel lines are all arranged along a second direction, the second direction is perpendicular to the first direction, and the first open branch and the second open branch are symmetrical about the first microstrip line, and the first three parallel lines and the second three parallel lines are symmetrical about the first microstrip line.

[0027] Furthermore, the first parallel three lines and the second parallel three lines each include a first transmission line, a second transmission line and a third transmission line that are parallel to each other, the second transmission line is located between the first transmission line and the third transmission line, the second transmission line is used to connect to the input end or the output end, and the first transmission line and the third transmission line are respectively used to connect to the first microstrip line.

[0028] Furthermore, the electrical lengths of the first microstrip line, the first open-circuit branch, the second open-circuit branch, the first parallel three-line, and the second parallel three-line are all one-quarter wavelength corresponding to the center frequency of the filter.

[0029] Another embodiment of the present invention further provides a filter, including a filter designed with any of the above-mentioned topological structures.

[0030] Furthermore, the filter also includes a circuit board, the dielectric loss of the circuit board is 0.0022, the thickness is 0.813 mm, and the size is 19.0 mm*10.0 mm.

[0031] refer to Figure 2 The line width of the transmission line in the first parallel three lines and the second parallel three lines is set to w p =0.4mm, line spacing is set to s p =0.1mm, line length is set to l p =6.9mm.

[0032] The length of the first microstrip line is set to l 1 =7.8mm, width is set to w 1 =1.2mm; the length of the first open branch and the second open branch is set to l 2 =7.9mm, width is set to w 2 =0.4mm.

[0033] According to microwave common sense, by changing the physical length l of the first three parallel lines and the second three parallel lines P , the physical length of the first microstrip line l 1 , the physical length l of the first open branch and the second open branch 2 The value of can change the operating frequency of the filter inversely. There are only four parameters that affect the performance of the filter, which are the spacing s between adjacent transmission lines that make up the first parallel three lines and the second parallel three lines. P , the transmission line width w of the first parallel three lines and the second parallel three lines P , the width w of the first microstrip line 1 , the width w of the first open branch and the second open branch 2 .

[0034] refer to Figure 3 It can be seen that as the parameter s P As the value increases, the passband bandwidth remains unchanged, the reflection coefficient in the passband becomes worse, and the isolation of the stopband becomes larger.

[0035] refer to Figure 4 It can be seen that as the parameter w P The change of the value of w will hardly change the bandwidth of the filter and the isolation of the stop band, but will change the reflection coefficient in the pass band. P When =0.4mm, the reflection coefficient in the passband is optimal.

[0036] refer to Figure 5 It can be seen that as the parameter w 1 As the value of becomes larger, the bandwidth of the bandpass filter becomes smaller and the isolation becomes smaller. 1 When =1.2mm, the in-band reflection coefficient is optimal.

[0037] refer to Figure 6 It can be seen that as the parameter w 2 As the value of becomes larger, the bandwidth of the bandpass filter becomes larger, the reflection coefficient at the passband edge becomes worse, and the stopband isolation becomes smaller.

[0038] Depend on Figure 3-6 From the analysis, we can see that the bandwidth of the filter designed based on this topology is mainly affected by the parameter w 1 and w 2 The reflection coefficient in the passband and the isolation in the stopband are controlled by the parameter s P 、w P 、w 1 、w 2 In addition, no matter how you change the parameter s P 、w P 、w 1 、w 2 , the filter designed based on this topology can only be a bandpass filter.

[0039] The bandpass filter corresponding to the above typical size is an ultra-wideband filter, and its S parameter simulation results are as follows: Figure 7 As shown. Figure 7 It can be seen that the impedance bandwidth with a reflection coefficient less than -10dB ranges from 3.65 to 9.73GHz, the passband center frequency is 6.69GHz, the passband absolute bandwidth is 6.08GHz, and the passband relative bandwidth is 90.9%. In addition, there are five transmission poles in the passband, located at 3.75, 4.65, 7.75, 8.21, and 9.55GHz, respectively. These five transmission poles ensure the flatness of the bandpass filter in the passband; there are two transmission zeros in the stopband, located at 3.21GHz and 10.15GHz, respectively. These two transmission poles can ensure the high selectivity of the filter.

[0040] Therefore, the ultra-wideband filter designed with the topological structure of this embodiment has the advantage of high selectivity.

[0041] The above description is only an optional embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A topology structure of a highly selective ultra-wideband filter, characterized in that: It includes a first microstrip line arranged along a first direction, wherein a first end of the first microstrip line is symmetrically connected to a first open branch node and a second open branch node, a second end of the first microstrip line is symmetrically connected to a first parallel three-wire and a second parallel three-wire, the other end of the first parallel three-wire is connected to an input end, and the other end of the second parallel three-wire is connected to an output end; The first open branch, the second open branch, the first three parallel lines and the second three parallel lines are all arranged along a second direction, the second direction is perpendicular to the first direction, and the first open branch and the second open branch are symmetrical about the first microstrip line, and the first three parallel lines and the second three parallel lines are symmetrical about the first microstrip line.

2. The topology of the highly selective ultra-wideband filter according to claim 1, characterized in that: The first parallel three-line and the second parallel three-line both include a first transmission line, a second transmission line and a third transmission line that are parallel to each other, the second transmission line is located between the first transmission line and the third transmission line, the second transmission line is used to connect to the input end or the output end, and the first transmission line and the third transmission line are respectively used to connect to the first microstrip line.

3. The topology of the highly selective ultra-wideband filter according to claim 1 is characterized in that: The electrical lengths of the first microstrip line, the first open-circuit branch, the second open-circuit branch, the first parallel three-line, and the second parallel three-line are all one-quarter wavelength corresponding to the center frequency of the filter.

4. A filter, characterized in that: A filter comprising a topology structure designed according to any one of claims 1 to 3.

5. The filter according to claim 4, characterized in that The filter also includes a circuit board, the dielectric loss of the circuit board is 0.0022, the thickness is 0.813 mm, and the size is 19.0 mm*10.0 mm.

6. The filter according to claim 4, characterized in that The line width of the transmission line in the first parallel three lines and the second parallel three lines is set to w p =0.4mm, line spacing is set to s p =0.1mm, line length is set to l p =6.9mm.

7. The filter according to claim 4, characterized in that The length of the first microstrip line is set to l1=7.8 mm, and the width is set to w1=1.2 mm; the length of the first open branch and the second open branch is set to l2=7.9 mm, and the width is set to w2=0.4 mm.

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