CN218957996U

CN218957996U - Filter

Info

Publication number: CN218957996U
Application number: CN202223529303.1U
Authority: CN
Inventors: 王天庭
Original assignee: Quectel Wireless Solutions Co Ltd
Current assignee: Quectel Wireless Solutions Co Ltd
Priority date: 2022-12-28
Filing date: 2022-12-28
Publication date: 2023-05-02
Anticipated expiration: 2032-12-28

Abstract

The application provides a filter, and relates to the technical field of electronic circuits. A filter, comprising: the device comprises a dielectric plate, two split resonant rings and an SIR resonator, wherein the two split resonant rings are symmetrically arranged, are arranged on the dielectric plate and are mutually coupled, and are used for carrying out filtering treatment on radio frequency signals passing through a first frequency band of the device; the SIR resonator is arranged on the dielectric plate and positioned in an area surrounded by the two split resonant rings, and is used for carrying out filtering processing on radio frequency signals passing through a second frequency band of the SIR resonator, and the SIR resonator comprises: the first resonance structure, the second resonance structure and the connecting microstrip line; the first resonant structure and the second resonant structure are connected through a connecting microstrip line, and the first resonant structure and the second resonant structure are symmetrical. When the radio frequency signals of the second frequency band are filtered, the two mutually coupled split resonant rings are used as signal transmission lines for transmitting the radio frequency signals of the second frequency band, so that the structure of the filter can be simplified.

Description

Filter

Technical Field

The present application relates to the technical field of electronic circuits, and in particular, to a filter.

Background

The band-pass filter is a key device of the radio frequency front ends of the receiver and the transmitter, and because the design development of the multi-frequency wireless communication system is rapid, the multi-frequency communication system becomes the dominant development direction of wireless communication in the future, wherein the wireless local area network and the broadband intercommunication microwave access dual-frequency filter are particularly important.

However, the existing dual-frequency filter wireless local area network and the broadband interworking microwave dual-frequency filter have complex structure and large volume, and are difficult to meet the increasing use demands.

Disclosure of Invention

The application provides a filter to solve the problem that the structure of the existing dual-frequency filter of wireless local area network and broadband intercommunication microwave is complex, the volume is big, and the ever-increasing use requirement is difficult to satisfy.

In a first aspect, the present application provides a filter comprising: the device comprises a dielectric plate, two split resonant rings and an SIR (step impedance resonator) resonator, wherein the two split resonant rings are symmetrically arranged, are arranged on the dielectric plate and are mutually coupled, and are used for carrying out filtering treatment on radio frequency signals passing through a first frequency band of the device; the SIR resonator is disposed on the dielectric plate and located in an area surrounded by the two split resonant rings, and is configured to perform filtering processing on a radio frequency signal passing through a second frequency band of the SIR resonator, and the SIR resonator includes: the device comprises a first resonance structure, a second resonance structure and a connecting microstrip line, wherein the frequency of the first frequency band is greater than that of the second frequency band; the first resonance structure and the second resonance structure are connected through the connecting microstrip line, and the first resonance structure and the second resonance structure are symmetrical.

In the embodiment of the application, the two mutually coupled split resonant rings are used for carrying out filtering processing on the radio frequency signals of the first frequency band, and the SIR resonator is used for carrying out filtering processing on the radio frequency signals of the second frequency band, so that the filtering of the radio frequency signals of the first frequency band and the radio frequency signals of the second frequency band is realized. When the SIR resonator is used for filtering the radio frequency signals of the second frequency band, the two mutually coupled split resonant rings are used as signal transmission lines for transmitting the radio frequency signals of the second frequency band, so that the structure of the filter can be simplified. Furthermore, the SIR resonator is arranged in the area surrounded by the two split resonant rings, so that the size of the filter can be effectively reduced.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the first resonant structure includes: and the rectangular conductive structure with one end open is provided with an opening, the amplitude of the opening is smaller than the side length of the side where the opening is positioned, and the connecting microstrip line passes through the opening and is connected with the rectangular conductive structure.

In this embodiment of the application, the first resonant structure includes a rectangular conductive structure with one end open, so that the first resonant structure can be manufactured conveniently, and the manufacturing difficulty is effectively reduced.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the first resonant structure includes: and the connecting microstrip line passes through the opening and is connected with the rectangular conductive structure.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the first resonant structure includes: and the width of the rectangular conductive structure is larger than that of the connecting microstrip line.

In the embodiment of the application, the first resonant structure is a rectangular conductive structure with the width larger than that of the connecting microstrip line, so that the first resonant structure is simplified, and the area of the first resonant structure is reduced.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the first resonant structure includes: the first microstrip line is vertically connected with one end of the connecting microstrip line; the second microstrip line is connected with one end of the first microstrip line far away from the connecting microstrip line, one end of the second microstrip line far away from the first microstrip line points to the second resonance structure, and the second microstrip line is not connected with the second resonance structure.

In the embodiment of the application, the first resonance structure can be obtained through the first microstrip line and the second microstrip line which are connected with each other, so that the first resonance structure is simple in structure, and the manufacturing difficulty is effectively reduced.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the first resonant structure includes: a third microstrip line, a fourth microstrip line and a fifth microstrip line, wherein the third microstrip line is vertically connected with one end of the connecting microstrip line; a fourth microstrip line is vertically connected with one end of the third microstrip line far away from the connecting microstrip line, and one end of the fourth microstrip line far away from the third microstrip line points to the second resonance structure; the fifth microstrip line is connected with one end of the fourth microstrip line far away from the third microstrip line, and one end of the fifth microstrip line far away from the fourth microstrip line points to the connecting microstrip line, and the fifth microstrip line is not connected with the second resonance structure.

In the embodiment of the application, the first resonant structure can be obtained through the third microstrip line, the fourth microstrip line and the fifth microstrip line, so that the design difficulty of the first resonant mechanism can be effectively reduced, and the manufacturing cost of the first resonant structure is reduced.

With reference to the foregoing technical solutions of the first aspect, in some possible implementation manners, the split resonant ring includes: the port microstrip line is used for receiving or outputting an electric signal; the amplitude of the opening is smaller than the side length of the side where the opening is located, and the port microstrip line is connected with one side, far away from the opening, of the rectangular conductive structure.

In the embodiment of the application, the open-ended resonant ring can be obtained through the port microstrip line and the rectangular conductive structure with one open end, so that the structure of the open-ended resonant ring is simplified, and the area of the open-ended resonant ring is reduced.

With reference to the foregoing technical solution provided by the first aspect, in some possible implementation manners, the rectangular conductive structure with one open end includes: a sixth microstrip line, a seventh microstrip line, an eighth microstrip line and a ninth microstrip line, wherein a first end of the sixth microstrip line is vertically connected with the port microstrip line, and the sixth microstrip line is not connected with an end point of the port microstrip line; the first end of the seventh microstrip line is vertically connected with the second end of the sixth microstrip line; the second end of the seventh microstrip line is vertically connected with the eighth microstrip line, and the seventh microstrip line is not connected with an endpoint of the eighth microstrip line; the first end of the port microstrip line is vertically connected with the ninth microstrip line, and the port microstrip line is not connected with an end point of the ninth microstrip line.

With reference to the foregoing technical solution of the first aspect, in some possible implementation manners, the longer the length from the end of the eighth microstrip line of the split-ring resonator close to the ninth microstrip line to the port microstrip line, the greater the resonant frequency of the split-ring resonator.

In the embodiment of the application, the split resonant ring with different resonant frequencies can be obtained by modifying the length from one end, close to the ninth microstrip line, of the eighth microstrip line of the split resonant ring to the port microstrip line, so that the range of the filter for filtering the radio frequency signals of the first frequency band is adjusted, and the application range of the filter of the scheme is wider.

In a second aspect, the present application provides a filter comprising: the device comprises an input end, an output end, a first resonant circuit, a second resonant circuit and a radio frequency filter circuit; a first end of the first resonant circuit is connected with the input end; the first end of the second resonant circuit is coupled with the second end of the first resonant circuit, and the second end of the second resonant circuit is connected with the output end, wherein the coupled first resonant circuit and the second resonant circuit are used for filtering the radio frequency signal of the first frequency band input by the input end and outputting the radio frequency signal of the first frequency band after the filtering through the output end; the first end of the radio frequency filter circuit is connected with the input end, the second end of the radio frequency filter circuit is connected with the output end, and the radio frequency filter circuit is used for carrying out filter processing on radio frequency signals of a second frequency band input by the input end and outputting the radio frequency signals of the second frequency band after the filter processing through the output end, wherein the frequency of the first frequency band is larger than that of the second frequency band.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a first filter according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a first SIR resonator according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a second SIR resonator according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a third SIR resonator according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of another four SIR resonators shown in the embodiments of the present application;

fig. 6 is a schematic structural diagram of yet another five SIR resonators shown in the embodiments of the present application;

fig. 7 is a schematic structural diagram of a second filter according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a third filter according to an embodiment of the present disclosure;

fig. 9 is a schematic diagram of a filtering frequency band of a first filter according to an embodiment of the present disclosure;

fig. 10 is a schematic diagram of a filtering frequency band of a second filter according to an embodiment of the present disclosure;

fig. 11 is a schematic diagram of a filtering frequency band of a third filter according to an embodiment of the present disclosure;

fig. 12 is a circuit schematic diagram of a fourth filter according to an embodiment of the present application.

Reference numerals: a 10-filter; 100-split resonator rings; 110-port microstrip lines; 120-sixth microstrip line; 130-seventh microstrip line; 140-eighth microstrip line; 150-ninth microstrip line; 200-SIR resonator; 210-a first resonant structure; 220-a second resonant structure; 230-connecting a microstrip line; 211-a first microstrip line; 212-a second microstrip line; 213-a third microstrip line; 214-a fourth microstrip line; 215-a fifth microstrip line; 300-dielectric plate.

Detailed Description

The terms "first," "second," "third," and the like are used merely for distinguishing between descriptions and not for indicating a sequence number, nor are they to be construed as indicating or implying relative importance.

In the description of the present application, unless explicitly stated and limited otherwise, the terms "configured to," "connected to," and "connected to" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements.

The technical solutions of the present application will be described in detail below with reference to the accompanying drawings.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a filter 10 according to an embodiment of the present application, where the filter 10 includes a dielectric plate 300, two split resonator rings 100 symmetrically disposed, and an SIR resonator 200.

The two split resonant rings 100 are disposed on the dielectric plate 300, and the two split resonant rings 100 are coupled to each other and are used for filtering the radio frequency signal passing through the first frequency band of the split resonant rings.

The SIR resonator 200 is disposed on the dielectric plate 300, and the SIR resonator is located in an area surrounded by the two split resonant rings 100, where the SIR resonator 200 is used to filter the radio frequency signal passing through the second frequency band of itself.

It is understood that the frequency of the first frequency band is greater than the frequency of the second frequency band. For example, the first band is 2.45GHZ and the second band is 5.2GHZ. By providing different split-rings 100 or SIR resonators 200, the frequency of the first frequency band or the second frequency band can be adjusted.

SIR resonator 200 includes: a first resonant structure 210, a second resonant structure 220, and a connecting microstrip line 230. The first and second

resonant structures

210 and 220 are connected by the connection microstrip line 230, and the first and second

resonant structures

210 and 220 are symmetrical.

The filtering process is performed on the radio frequency signals passing through the first frequency band of the split resonant ring 100 through the two split resonant rings which are coupled with each other, and the filtering process is performed on the radio frequency signals passing through the second frequency band through the SIR resonator 200, so that the filtering of the radio frequency signals of the first frequency band and the radio frequency signals of the second frequency band is realized. When the SIR resonator 200 is used to filter the radio frequency signal in the second frequency band, the two split resonant rings 100 that are coupled to each other are used as signal transmission lines for transmitting the radio frequency signal in the second frequency band, so that the structure of the filter 10 can be simplified. Further, the SIR resonator 200 is provided in the region surrounded by the two split resonator rings 100, and the volume of the filter 10 can be effectively reduced.

The dielectric plate may be any type of dielectric plate, for example, a Taconic TLX dielectric plate, which has a dielectric constant of 2.55, a loss tangent of 0.0019, a thickness of 0.5mm, and a dimension of 34.25mm by 27.4mm. The examples herein are for ease of understanding only and should not be construed as limiting the present application.

Since the first and second

resonant structures

210 and 220 are symmetrical, the first and second

resonant structures

210 and 220 are identical.

In practical applications, when the radio frequency signal in the second frequency band needs to be filtered, the radio frequency signal in the second frequency band is coupled to the first resonant structure 210 of the SIR resonator 200 through the split ring resonator 100, so that the SIR resonator 200 performs filtering processing on the radio frequency signal in the second frequency band passing through itself, and couples the radio frequency signal in the second frequency band after the filtering processing to another split resonator through the second resonant structure 220 of the SIR resonator 200, and outputs the radio frequency signal in the second frequency band after the filtering processing. In this process, the two split resonator rings 100 act as signal transmission lines.

When the radio frequency signals of the first frequency band need to be filtered, the radio frequency signals of the first frequency band are coupled to the other split-ring resonator 100 through the split-ring resonator 100, and the two split-ring resonators 100 coupled with each other cooperate with each other to jointly complete the filtering process of the radio frequency signals of the first frequency band.

In order to simplify the structure of the filter 10 and reduce the volume of the filter 10, in one embodiment, the structure of the SIR resonator 200 may be simplified and the volume of the SIR resonator 200 may be reduced, thereby achieving the purposes of simplifying the structure of the filter 10 and reducing the volume of the filter 10. The specific structure of SIR resonator 200 may be the following five embodiments.

In the first embodiment, the first resonant structure 210 includes a rectangular conductive structure with an opening at one end, and the width of the opening is smaller than the side length of the side where the opening is located, and the connection microstrip line 230 is connected to the rectangular conductive structure through the opening. For ease of understanding, please refer to fig. 2.

At this time, the adjustment of the resonance frequency of the SIR resonator 200 may be achieved by adjusting the length of the rectangular conductive structure, the longer the rectangular conductive structure (L in fig. 2), the larger the resonance frequency of the SIR resonator 200. Since the resonance frequency of the SIR resonator 200 is the same as the filtering range of the corresponding filter 10, the range of the filter 10 for filtering the radio frequency signal in the second frequency band can be adjusted by the length of the rectangular conductive structure, so that the application range of the filter 10 in the present embodiment is wider.

The side lengths of the four sides of the rectangular conductive structure may not be identical, and a user may set the rectangular conductive structure according to actual requirements, which is not limited herein.

The rectangular conductive structure with one end open can be integrally formed; or may be separately manufactured and then connected.

In a second embodiment, the first resonant structure 210 comprises: a rectangular conductive structure with one end open, and the width of the opening is equal to the side length of the side where the opening is located, and the connection microstrip line 230 passes through the opening to be connected with the rectangular conductive structure. For ease of understanding, please refer to fig. 3.

In a third embodiment, the first resonant structure 210 comprises: the rectangular conductive structure has a width larger than that of the connection microstrip line 230. For ease of understanding, please refer to fig. 4.

The length of the rectangular conductive structure in the Y-axis direction in fig. 4 is the width of the rectangular conductive structure, and the length of the rectangular conductive structure in the X-axis direction in fig. 4 is the length of the rectangular conductive structure.

The rectangular conductive structure may be integrally formed; or may be separately manufactured and then connected.

In a fourth embodiment, the first resonant structure 210 comprises: a first microstrip line 211 and a second microstrip line 212, wherein the first microstrip line 211 is vertically connected with one end of the connection microstrip line 230; the second microstrip line 212 is connected to one end of the first microstrip line 211 remote from the connection microstrip line 230, and one end of the second microstrip line 212 remote from the first microstrip line 211 is directed to the second resonant structure 220, and the second microstrip line 212 is not connected to the second resonant structure 220. Accordingly, an end of the second microstrip line 212 of the second resonant structure 220 remote from the first microstrip line 211 is directed toward the first resonant structure 210. For ease of understanding, please refer to fig. 5.

Wherein, the first microstrip line 211 and the second microstrip line 212 may be integrally formed; or may be separately manufactured and then connected. The first resonant structure is divided into the first microstrip line 211 and the second microstrip line 212 in fig. 5 only for easy understanding, and may be divided in other ways, which should not be taken as a limitation of the present application.

In a fifth embodiment, the first resonant structure 210 comprises: a third microstrip line 213, a fourth microstrip line 214, and a fifth microstrip line 215, the third microstrip line 213 being vertically connected to one end of the connection microstrip line 230; the fourth microstrip line 214 is vertically connected with one end of the third microstrip line 213 far from the connection microstrip line 230, and one end of the fourth microstrip line 214 far from the third microstrip line 213 is directed toward the second resonant structure 220; the fifth microstrip line 215 is connected to one end of the fourth microstrip line 214 far from the third microstrip line 213, and one end of the fifth microstrip line 215 far from the fourth microstrip line 214 is directed to the connection microstrip line 230, and the fifth microstrip line 215 is not connected to the second resonant structure 220. Accordingly, an end of the fourth microstrip line 214 of the second resonant structure 220 remote from the third microstrip line 213 is directed toward the first resonant structure 210. For ease of understanding, please refer to fig. 6.

Wherein the third microstrip line 213, the fourth microstrip line 214, and the fifth microstrip line 215 may be integrally formed; or may be separately manufactured and then connected. The division of the first resonant structure into the third microstrip line 213, the fourth microstrip line 214 and the fifth microstrip line 215 in fig. 5 is only for easy understanding, and may be divided in other ways, which should not be taken as a limitation of the present application.

In order to simplify the structure of the filter 10 and reduce the volume of the filter 10, the structure of the split ring resonator 100 may be simplified and the volume of the split ring resonator 100 may be reduced, thereby achieving the purpose of simplifying the structure of the filter 10 and reducing the volume of the filter 10.

In one embodiment, split resonator ring 100 comprises: a port microstrip line 110 and a rectangular conductive structure with one end open.

The port microstrip line 110 is used to receive or output an electrical signal. The width of the opening of the rectangular conductive structure with one opening is smaller than the side length of the side where the opening is located, and the port microstrip line 110 is connected with one side of the rectangular conductive structure away from the opening. For ease of understanding, please refer to fig. 7.

Wherein the impedance of the port microstrip lines 110 of different split-rings 100 may be the same, for example, may be set to 50 ohms. The impedance of the port microstrip lines 110 of the different split-ring resonators 100 is set to be the same, so that problems such as efficiency degradation and performance degradation caused by impedance mismatch when electromagnetic waves propagate between devices can be prevented.

In one embodiment, a specific structure of a rectangular conductive structure with one end open may include: a sixth microstrip line 120, a seventh microstrip line 130, an eighth microstrip line 140, and a ninth microstrip line 150.

The first end of the sixth microstrip line 120 is vertically connected to the port microstrip line 110, and the sixth microstrip line 120 is not connected to an end point of the port microstrip line 110; the first end of the seventh microstrip line 130 is vertically connected to the second end of the sixth microstrip line 120; the second end of the seventh microstrip line 130 is vertically connected to the eighth microstrip line 140, and the seventh microstrip line 130 is not connected to an end point of the eighth microstrip line 140; the first end of the port microstrip line 110 is connected perpendicularly to the ninth microstrip line 150, and the port microstrip line 110 is not connected to an end point of the ninth microstrip line 150.

Wherein the sixth microstrip line 120, the seventh microstrip line 130, the eighth microstrip line 140, and the ninth microstrip line 150 may be integrally formed; or may be separately manufactured and then connected. The division of the rectangular structure with one open end into the sixth microstrip line 120, the seventh microstrip line 130, the eighth microstrip line 140 and the ninth microstrip line 150 in fig. 7 is only for easy understanding, and may be divided in other ways, which should not be taken as a limitation of the present application.

Here, the longer the length (W shown in fig. 7) from the end of the eighth microstrip line 140 of the split ring resonator 100 near the ninth microstrip line 150 to the port microstrip line 110, the larger the resonance frequency of the split ring resonator 100. The length from the end, close to the ninth microstrip line 150, of the eighth microstrip line 140 of the split-ring resonator 100 to the port microstrip line 110 can be modified to obtain split-ring resonators 100 with different resonant frequencies, so that the range of the filter 10 for filtering the radio frequency signals of the first frequency band can be adjusted, and the application range of the filter 10 in the scheme is wider.

The two split resonator rings 100 may be axisymmetric or may be centrosymmetric, and the two split resonator rings 100 shown in fig. 7 are centrosymmetric. The two split resonant rings 100 shown in fig. 8 are axisymmetric.

The split ring resonator 100 and SIR resonator 200 are made of conductive materials, such as conductive metals (copper, iron, gold, silver, etc.), graphite, etc. Alternatively, both split ring resonator 100 and SIR resonator 200 may be constructed using microstrip lines.

In one embodiment, in order to facilitate understanding of the actual influence of L in fig. 2 and W in fig. 7 on the filter 10, the filter 10 shown in fig. 7 is taken as an example.

The filtering range of the low frequency band can be adjusted by modifying the length of W, taking W as 1mm, 2mm and 3mm respectively, as shown in fig. 9. The low frequency band signal passing through the filter 10 varies in the range of 2.0-2.5GHz and has substantially no effect on the high frequency band signal passing through the filter 10.

The filtering range of the high-frequency band can be adjusted by modifying the length of L, taking L as 4mm, 4.5mm and 5mm respectively as an example, as shown in fig. 10. The high frequency band signal passing through the filter 10 varies in the range of 5.0-5.4GHz and has substantially no effect on the low frequency band signal passing through the filter 10.

The filter 10 provided by the scheme has four transmission zeros outside the passband, so that not only can the higher band selectivity be ensured, but also the out-of-band suppression effect can be improved. For ease of understanding, please refer to fig. 11. Fig. 11 shows the result of practical application of the filter 10 shown in fig. 7. Where S11 is the return loss and S12 is the insertion loss.

As can be seen from fig. 11, the filter 10 operates at 2.4GHz and 5.2GHz with 3db bandwidths of 360MHz and 440MHz. The insertion loss in the passband of the low frequency band is 0.35dB, and the return loss is 20dB; the insertion loss in the passband of the high band is 0.33dB and the return loss is 30dB. The four transmission zeroes are 1.95GHz, 3.13GHz, 4.94Ghz and 6.12GHz, respectively, which correspond to 67dB, 48dB, 32dB and 46dB, respectively, of insertion loss. Four transmission zeroes can be seen at the edges of the passband, indicating that the filter 10 has good frequency selective characteristics.

Referring to fig. 12, fig. 12 is a schematic circuit diagram of a filter according to an embodiment of the present application, including: an input terminal, an output terminal, a first resonance circuit (L1 in fig. 12), a second resonance circuit (L2 in fig. 12), and a radio frequency filter circuit.

The first end of the first resonant circuit is connected with the input end. The first end of the second resonant circuit is coupled with the second end of the first resonant circuit, and the second end of the second resonant circuit is connected with the output end, wherein the coupled first resonant circuit and the coupled second resonant circuit are used for carrying out filtering processing on the radio frequency signals of the first frequency band input by the input end and outputting the radio frequency signals of the first frequency band after the filtering processing through the output end. The radio frequency signal of the first frequency band flows to Route1 in fig. 12.

The first end of the radio frequency filter circuit is connected with the input end, the second end of the radio frequency filter circuit is connected with the output end, and the radio frequency filter circuit is used for carrying out filter processing on radio frequency signals of a second frequency band input by the input end and outputting the radio frequency signals of the second frequency band after the filter processing through the output end. The flow of the radio frequency signal in the second frequency band is shown as Route2 in fig. 12.

In one embodiment, the rf filter circuit includes a first capacitor (Cg on the left in fig. 12), a third resonant circuit (L3 in fig. 12), and a second capacitor (Cg on the right in fig. 12) in series.

The rf filter circuit in the filter shown in fig. 12 corresponds to the SIR resonator in the filter shown in fig. 1, and the rf filter circuit in the first frequency band in the filter shown in fig. 12 corresponds to the two split-resonator rings 100 symmetrically arranged in the filter 10 shown in fig. 1.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A filter, comprising:

a dielectric plate;

the two split resonant rings are symmetrically arranged, are arranged on the dielectric plate and are mutually coupled and are used for carrying out filtering treatment on radio frequency signals passing through a first frequency band of the split resonant rings;

SIR resonator, SIR resonator set up in on the dielectric plate, and be located two split ring surrounds the regional, SIR resonator is used for carrying out filter processing to the radio frequency signal through self second frequency channel, SIR resonator includes: the device comprises a first resonance structure, a second resonance structure and a connecting microstrip line, wherein the frequency of the first frequency band is greater than that of the second frequency band; the first resonant structure and the second resonant structure are connected through the connecting microstrip line, and

the first resonant structure and the second resonant structure are symmetrical.

2. The filter of claim 1, wherein the first resonant structure comprises:

and the rectangular conductive structure with one end open is provided with an opening, the amplitude of the opening is smaller than the side length of the side where the opening is positioned, and the connecting microstrip line passes through the opening and is connected with the rectangular conductive structure.

3. The filter of claim 1, wherein the first resonant structure comprises:

and the connecting microstrip line passes through the opening and is connected with the rectangular conductive structure.

4. The filter of claim 1, wherein the first resonant structure comprises:

and the width of the rectangular conductive structure is larger than that of the connecting microstrip line.

5. The filter of claim 1, wherein the first resonant structure comprises:

the first microstrip line is vertically connected with one end of the connecting microstrip line;

the second microstrip line is connected with one end of the first microstrip line far away from the connecting microstrip line, one end of the second microstrip line far away from the first microstrip line points to the second resonance structure, and the second microstrip line is not connected with the second resonance structure.

6. The filter of claim 1, wherein the first resonant structure comprises:

the third microstrip line is vertically connected with one end of the connecting microstrip line;

a fourth microstrip line vertically connected with one end of the third microstrip line far from the connection microstrip line, and one end of the fourth microstrip line far from the third microstrip line points to the second resonance structure;

and the fifth microstrip line is connected with one end of the fourth microstrip line far away from the third microstrip line, one end of the fifth microstrip line far away from the fourth microstrip line points to the connecting microstrip line, and the fifth microstrip line is not connected with the second resonance structure.

7. The filter of claim 1, wherein the split resonator ring comprises:

a port microstrip line for receiving or outputting an electrical signal;

and the port microstrip line is connected with one side of the rectangular conductive structure far away from the opening.

8. The filter of claim 7, wherein the rectangular conductive structure having one end open comprises:

a sixth microstrip line, wherein a first end of the sixth microstrip line is vertically connected with the port microstrip line, and the sixth microstrip line is not connected with an end point of the port microstrip line;

a seventh microstrip line, wherein a first end of the seventh microstrip line is vertically connected with a second end of the sixth microstrip line;

an eighth microstrip line, a second end of the seventh microstrip line being vertically connected to the eighth microstrip line, and the seventh microstrip line not being connected to an end point of the eighth microstrip line;

and the port microstrip line is not connected with the end point of the ninth microstrip line.

9. The filter according to claim 8, wherein the longer the length of the eighth microstrip line of the split ring from the end near the ninth microstrip line to the port microstrip line, the larger the resonance frequency of the split ring.

10. A filter, comprising:

an input end;

an output end;

the first end of the first resonant circuit is connected with the input end;

the first end of the second resonant circuit is coupled with the second end of the first resonant circuit, and the second end of the second resonant circuit is connected with the output end; the first resonant circuit and the second resonant circuit are coupled and connected, and are used for carrying out filtering processing on the radio frequency signals of the first frequency band input by the input end and outputting the radio frequency signals of the first frequency band after the filtering processing through the output end;

the radio frequency filter circuit is used for carrying out filter processing on radio frequency signals of a second frequency band input by the input end and outputting the radio frequency signals of the second frequency band after the filter processing by the output end, wherein the frequency of the first frequency band is larger than that of the second frequency band.