CN114301409A - Low-pass band-stop filter and filter circuit, filter module and tuning method thereof - Google Patents

Abstract

The invention relates to a low-pass band-stop filter, a low-pass band-stop filter circuit, a low-pass band-stop filter module and a tuning method thereof, which can not only theoretically realize the requirement of near passband suppression, but also realize physical design in actual processing, and have simple and convenient processing. Meanwhile, the characteristics of ultra-wideband and near-passband strong suppression can be considered. Moreover, under the condition of realizing the same difficulty index, the volume is favorably reduced, and the cost is lower. Moreover, each capacitor element is realized by the guide belt piece, and the structure is simple and reliable, high in stability and good in consistency.

Description

Low-pass band-stop filter and filter circuit, filter module and tuning method thereof

technical field

The present invention relates to the technical field of communication devices, in particular to a low-pass band-reject filter and its low-pass band-reject filter circuit, a low-pass band-reject filter module and a tuning method.

Background technique

As a very critical device in the field of communication, the filter can allow useful signals to pass through the signal link to the greatest extent and suppress useless signals to the greatest extent. In view of the current situation of multi-mode and multi-frequency coexisting networks, there is an increasing demand for low-pass band-stop filters with strong near-pass band suppression. field has been widely used. Low-pass band-stop filter The traditional low-pass band-stop filter module is usually composed of an inductor on the series arm and a capacitor on the parallel arm or an LC series resonator on the parallel arm. For low-pass band-stop filters with near-pass-band rejection requirements, there are two problems in the theoretical synthesis of circuit parameters obtained by using traditional low-pass band-stop filter modules: first, a negative inductance will appear on the series arm. , resulting in an unrealizable physical design; second, the inductance value of the LC series resonator on the parallel arm is too large (generally hundreds of nH), and the capacitance is too small, so such LC series resonance cannot be realized physically. Especially for the low passband rejection filter with the highest passband frequency in the microwave frequency band, it is totally impossible to realize such LC series resonator design with distributed parameters.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a low-pass band-reject filter and its low-pass band-reject filter circuit, a low-pass band-reject filter module and a tuning method for the problem that physical design cannot be realized.

Its technical solutions are as follows:

In one aspect, a low-pass band-stop filter circuit is provided, including a series arm and a parallel arm;

The parallel arm includes a three-device resonance unit;

The series arm includes N first inductances connected in series between the input terminal and the output terminal; wherein, the connection node between the i-th first inductance and the (i+1)-th first inductance passes through the three The device resonance unit is connected to the ground terminal, and N is a positive integer greater than or equal to 2, i is a positive integer greater than or equal to 1, and i is less than N.

The technical solution is further described below:

In one of the embodiments, the parallel arm further includes a first capacitor; wherein the connection node between the i+1 th first inductor and the (i+2) th first inductor is connected through the first capacitor A ground terminal, and N is a positive integer greater than or equal to 3, i is a positive integer greater than or equal to 1, and i is less than N.

In one of the embodiments, the three-device resonance unit includes an LC series resonator and a second capacitor connected in parallel with the LC series resonator.

In one of the embodiments, the three-device resonant unit includes a three-device resonant equivalent circuit.

In one of the embodiments, the three-device resonant equivalent circuit includes an LC parallel resonator, a third capacitor connected in series with the LC parallel resonator, and a series connection between the third capacitor and the LC parallel resonator The fourth capacitor is connected in parallel with the structure.

In another aspect, a low-pass band-stop filter circuit is provided, comprising a series arm and a parallel arm;

the parallel arm includes a fifth capacitor;

The series arm includes M first series units and H second series units connected in series between the input terminal and the output terminal, and the M first series units and the H second series units are alternately arranged, Wherein, the first series unit includes a three-device resonant unit for avoiding negative value inductance on the series arm, and the second series unit includes a second inductance; or, the first series unit includes a second inductance , the second series unit includes a three-device resonance unit for avoiding negative inductance on the series arm, and M and H are both positive integers greater than 1;

Wherein, the connection node between the first series unit and the second series unit is connected to the ground terminal through the fifth capacitor.

In one of the embodiments, the three-device resonance unit includes a third inductor and an LC parallel resonator connected in series with the third inductor.

In another aspect, a low-pass band-reject filter module using the low-pass band-reject filter circuit is provided, including:

A conductive cavity, the conductive cavity is provided with an installation slot, a resonant cavity arranged on the side of the installation slot, a communication slot for connecting the installation slot and the resonant cavity, and a resonant cavity arranged in the resonant cavity the resonant column;

a first tape guide member, the first tape guide member is disposed in the installation groove and used to form the series arm and the first capacitor, and the first tape guide member is provided with a branch extending toward the communication groove;

a second band-conducting element, one end of the second band-conducting element is electrically connected to the resonant column, and the other end of the second band-conducting element is coupled with the branch to form the third capacitor; and

a cover body, the cover body is covered above the conductive cavity, the cover body is spaced apart from the resonant column and cooperates with the resonant column to form the LC parallel resonator;

Wherein, the conductive cavity is further provided with a coupling portion, and the coupling portion can be coupled and matched with the branch to form the fourth capacitor.

In one embodiment, the inner side wall of the communication groove is provided with a partition wall.

In one of the embodiments, there are at least two resonant cavities, at least two of the resonant cavities are distributed on the same side of the installation groove, or at least two of the resonant cavities are staggered and distributed opposite to the installation groove on both sides.

In one embodiment, the low-pass band-stop filtering module further includes an input connector and an output connector, and the input connector and the output connector are respectively electrically connected to opposite ends of the first tape conducting member.

In one embodiment, the low-pass band-stop filter module further includes an insulating support member for supporting the first tape guide member and/or the second tape guide member.

In another aspect, a low-pass band-stop filter is provided, which is designed by using the low-pass band-stop filtering circuit; and/or using the low-pass band-stop filtering module.

In yet another aspect, a tuning method applied to the low-pass band-stop filter module is provided, wherein the third capacitance is adjusted by adjusting the coupling degree between the branch and the second conduction band member and/or by adjusting the degree of coupling between the coupling part and the branch to adjust the size of the fourth capacitor; and/or by adjusting the degree of coupling between the cover and the resonant column to adjust the Parameters of LC parallel resonators.

The low-pass band-reject filter and its low-pass band-reject filter circuit, low-pass band-reject filter module and tuning method of the above embodiments can not only theoretically achieve near-pass band suppression requirements, but also realize physical design from actual processing. , processing is simple and convenient. At the same time, it can take into account the characteristics of ultra-wideband and strong suppression of near-passband. Moreover, in the case of achieving the same difficulty index, it is beneficial to reduce the volume and lower the cost. In addition, each capacitive element is realized by using the conduction band, the structure is simple and reliable, the stability is high, and the consistency is good.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Figure 1 is a circuit diagram of a traditional low-pass band-stop filter;

2 is a circuit diagram of a low-pass band-stop filter of a pass filter according to an embodiment of the application;

3 is an equivalent circuit diagram of a three-device resonance unit of the low-pass band-stop filter circuit of FIG. 2;

Fig. 4 is the dual circuit of the low-pass band-stop filter circuit of Fig. 2;

5 is a schematic structural diagram of a low-pass band-stop filter module of a low-pass band-stop filter according to an embodiment;

Fig. 6 is the top view of the low-pass band-stop filter module of the low-pass band-stop filter of Fig. 5;

Fig. 7 is the assembly schematic diagram of the second band conduction part of the low-pass band-stop filter module of the low-pass band-stop filter of Fig. 5;

8 is an assembly schematic diagram of a resonant column, a first band-conducting member, and a second band-conducting member of the low-pass band-stop filter module of the low-pass band-stop filter of FIG. 5;

FIG. 9 is a schematic structural diagram of a conductive cavity of a low-pass band-reject filter module of the low-pass band-reject filter of FIG. 5 .

Description of reference numbers:

10. Low-pass band-stop filter module; 100, conductive cavity; 110, installation slot; 120, resonant cavity; 130, communication slot; 140, resonant column; 150, coupling part; 160, partition wall; 170, input connector; 180, output connector; 190, insulating support; 200, first tape conductor; 210, branch; 300, second tape conductor; 400, cover body; 500, first capacitor; 600, three-device resonance unit; 610 620, the third capacitance; 630, the fourth capacitance; 700, the first inductance; 800, the fifth capacitance; 900, the second inductance; 1000, the third inductance.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

The traditional low-pass band-stop filter circuit is shown in Figure 1, which is a ladder network composed of the inductor on the series arm and the capacitor on the parallel arm or the LC series resonator on the parallel arm, the dual form of the traditional low-pass band-stop filter circuit. It is a ladder network composed of a series inductance on the series arm or a parallel LC resonator and a capacitor on the parallel arm. When there is a requirement for near-pass band suppression, a negative value inductance will appear on the series arm of the traditional low-pass band-stop filter circuit, and the traditional The capacitance on the parallel arm and the inductance on the series arm of the dual circuit of the low-pass band-stop filter circuit will have negative values, resulting in an unrealizable physical design, or the inductance value of the LC series resonator on the parallel arm is too large, If the capacitance is too small, such a design cannot be achieved physically, resulting in difficult or impossible processing.

In one embodiment, a low-pass band-stop filter circuit is provided, which can not only achieve near-pass-band suppression requirements in theory, but also realize physical design from actual processing, and the processing is simple and convenient.

Wherein, the low-pass band-stop filter circuit includes a series arm and a parallel arm.

As shown in FIG. 2 , in particular, the parallel arm includes a three-device resonance unit 600 for avoiding negative value inductance on the series arm.

Wherein, the series arm includes N first inductors 700 connected in series between the input terminal and the output terminal, thereby forming a ladder network.

The connection node between the i-th first inductor 700 and the (i+1)-th first inductor 700 is connected to the ground terminal through the three-device resonance unit 600, and N is a positive integer greater than or equal to 2, and i is greater than or equal to 2 A positive integer equal to 1, and i is less than N, that is, a three-device resonance unit 600 may be provided between two adjacent first inductors 700 .

Of course, a three-device resonant unit 600 may also be provided between two adjacent first inductors 700 , while no three-device resonant unit 600 is provided between two partially adjacent first inductors 700 . Practical use requires flexible design or adjustment.

Optionally, the parallel arm further includes a first capacitor 500 ; wherein the connection node between the (i+1)th first inductor 700 and the (i+2)th first inductor 700 is connected to ground through the first capacitor 500 terminal, and N is a positive integer greater than or equal to 3, i is a positive integer greater than or equal to 1, and i is less than N.

Optionally, when N is equal to 3 and i is equal to 1, the connection node between the first first inductor 700 and the second first inductor 700 is connected to the ground terminal through the three-device resonance unit 600, and the second first inductor 700 is connected to the ground terminal. The connection node between 700 and the third first inductor 700 is connected to the ground terminal through the first capacitor 500 , and the connection node between the third first inductor 700 and the fourth first inductor 700 is connected through the three-device resonance unit 600 The ground terminal, the connection node between the fourth first inductor 700 and the fifth first inductor 700 is connected to the ground terminal through the first capacitor 500, and so on.

It should be noted that the three-device resonant unit 600 not only refers to a circuit that uses three electrical components to implement the corresponding resonator function, but also refers to a circuit that uses three or more electrical components to equivalently implement the corresponding resonator function. The circuit only needs to be able to avoid the negative value inductance on the series arm and be able to physically process it.

As shown in FIG. 2 and FIG. 3( a ), optionally, the three-device resonance unit 600 includes an LC series resonator and a second capacitor 610 connected in parallel with the LC series resonator. In this way, an inductive element and a capacitive element are connected in series to form an LC series resonator, and then connected in parallel with the second capacitor 610 to form a three-device resonance unit 600, and then the three-device resonance unit 600 can be connected in parallel to the series arm. In addition, the use of the three-device resonant unit 600 can also avoid the occurrence of negative value inductance on the series arm.

As shown in FIG. 3( b ), optionally, the three-device resonance unit 600 includes a three-device resonance equivalent circuit. In this way, the use of the three-device resonant equivalent circuit can also avoid negative inductance on the series arm, and can be processed physically.

Specifically, the three-device resonance equivalent circuit includes an LC parallel resonator, a third capacitor 620 connected in series with the LC parallel resonator, and a fourth capacitor 630 connected in parallel with the series structure of the third capacitor 620 and the LC parallel resonator. In this way, an inductive element and a capacitive element are connected in parallel to form an LC parallel resonator and then connected in series with the third capacitor 620. The series structure formed by the LC parallel resonator and the third capacitor 620 in series is then connected in parallel with the fourth capacitor 630 to form three capacitors. The device resonance equivalent circuit can avoid negative inductance on the series arm, and can be processed physically.

It should be noted that the dual circuit of FIG. 2 is a three-device resonant unit 600 composed of an inductance or an inductance in series with an LC parallel resonator on the series arm, and a network composed of capacitors on the parallel arm. Those skilled in the art know that, The two circuits are completely interchangeable.

As shown in FIG. 4 , in one embodiment, another low-pass band-stop filter circuit is provided, including a series arm and a parallel arm.

The parallel arm includes a fifth capacitor 800 .

The series arm includes M first series units and H second series units connected in series between the input terminal and the output terminal, and the M first series units and the H second series units are alternately arranged, wherein the first series units are alternately arranged. The series unit includes a three-device resonance unit 600 for avoiding negative inductance on the series arm and negative capacitance on the parallel arm, the second series unit includes a second inductance 900; or, the first series unit includes a second inductance 900, The second series unit includes a three-device resonance unit 600 for avoiding negative inductance on the series arm, and M and H are both positive integers greater than 1.

The connection node between the first series unit and the second series unit is connected to the ground terminal through the fifth capacitor 800 .

As shown in FIG. 4 , optionally, the three-device resonance unit 600 includes a third inductor 1000 and an LC parallel resonator connected in series with the third inductor 1000 .

It should be noted that the alternate arrangement of M first series units and H second series units means that one second series unit or two adjacent second series units are arranged between two adjacent first series units. A first series unit is arranged between the series units.

In order to facilitate the description of the principles of the embodiments of the present application, FIG. 2 is used as an example for description below, and those skilled in the art should not understand the limitations of the embodiments of the present application.

The circuit of the three-device resonator unit in FIG. 2 can be equivalent to the circuit of FIG. 3(a), and the circuit of FIG. 3(a) can be equivalent to the circuit of FIG. 3(b).

Specifically, the circuit of Fig. 3(a) is completely equivalent to the circuit of Fig. 3(b) under the following conditions:

C _x0,2 =C _0,2 +C ₂ (1)

L _x2 = (C ₂ /C _m ) ² L ₂ (2)

The port admittance of the equivalent circuit in Fig. 3(b) is:

where s is the angular frequency multiplied by a unit imaginary number and _{km is the coupling coefficient between C x0,2 and} the parallel resonator L _x2 C _x2 :

It can be known from (5) that the port admittance of the equivalent circuit of the three-device resonant unit 600 has nothing to do with the specific values of the inductance and capacitance in the parallel LC parallel resonator. Difficulties in physical implementation caused by device values that are too large or too small.

In addition, through the circuit of Fig. 3(b), each resonator that realizes the attenuation pole of the low-pass band-rejection filter is designed, so as to meet the requirement of suppression outside the pass-band.

In one embodiment, a low-pass band-reject filter module 10 using a low-pass band-reject filter circuit is provided, and the low-pass band-reject filter circuit can not only theoretically achieve the near-pass band rejection requirement, but also be capable of practical processing. The physical design is realized in the middle, and the processing is simple and convenient.

As shown in FIG. 5 to FIG. 9 , specifically, the low-pass band-stop filter module 10 includes a conductive cavity 100 , a first tape guide member 200 , a second tape guide member 300 and a cover 400 .

As shown in FIG. 5 , FIG. 6 and FIG. 9 , the conductive cavity 100 is used as the main structure, which can be obtained by casting a metal conductive material or the like. Specifically, an installation slot 110 is extended in the length direction of the conductive cavity 100 (as shown in the direction A of FIG. 6 ), a resonant cavity 120 is arranged on the side of the installation slot 110 , and the installation slot 110 and the resonant cavity 120 are arranged There is a communication slot 130 between the mounting slot 110 and the resonant cavity 120, and at the same time, a resonant column 140 is arranged in the resonant cavity 120 along the height direction of the conductive cavity 100. It is obtained by one-piece molding, which is easy to process. Also, the resonant column 140 itself may be equivalent to an inductive element.

Of course, in other embodiments, the resonant column 140 and the conductive cavity 100 are assembled and connected by means of screwing or clipping after being formed respectively.

As shown in FIG. 6 and FIG. 8 , the first tape guide member 200 can be in the shape of a sheet or a strip, and can be installed in the installation slot 110 by means of plugging, clipping, etc. and extending along the length direction of the conductive cavity 100 . . At the same time, the series arm and the first capacitor 500 can be formed by using the first tape conduction member 200 .

Specifically, a ladder network including at least three first inductances 700 connected in series can be realized by changing the narrow width of the first tape conduction member 200 . More specifically, the width of the first tape conduction member 200 periodically changes in size along the length direction of the conductive cavity 100 , so that it is equivalent to at least three first inductances 700 connected in series at the high characteristic impedance portion, thereby forming a trapezoidal shape. network. In addition, the first capacitor 500 is formed at a distance between the low characteristic impedance part and the inner wall of the mounting groove 110 . The first tape conducting member 200 is made a distributed parameter device.

In addition, a branch 210 extending toward the communication groove 130 is provided on the side of the first tape guide member 200 close to the resonant cavity 120 .

As shown in FIG. 6 to FIG. 8 , the second tape guide member 300 may be in the shape of a sheet or a strip, and one end of the second tape guide member 300 may be connected to the resonance column 140 by welding, welding or screwing. The other ends of the second tape guide members 300 extend toward the direction close to the first tape guide member 200 and are coupled with the branch 210 to form a third capacitor 620 .

As shown in FIG. 5 , the cover body 400 may be in the shape of a plate, and the cover body 400 is placed above the conductive cavity 100 and connected to the conductive cavity 100 by means of screw connection, etc., so that the installation grooves 110 , The cavity structures such as the resonant cavity 120 and the communication groove 130 are closed. At the same time, after the cover plate is placed above the conductive cavity 100, the cover plate and the top of the resonant column 140 are spaced apart to be equivalent to a capacitive element, and combined with the resonant column 140 itself, it is equivalent to an inductive element, so that the cover plate is Cooperating with the resonant column 140 to form an LC parallel resonator, that is, an inductive element and a capacitive element are connected in parallel to form the LC parallel resonator. And, the LC parallel resonator is connected in series with the third capacitor 620 .

As shown in FIG. 9 , in addition, a coupling portion 150 is provided at the bottom of the conductive cavity 100 and below the branch 210 , and the coupling portion 150 and the branch 210 are spaced and coupled, so that the coupling portion 150 and the branch 210 cooperate to form a fourth Capacitor 630. In addition, the circuit composed of the LC parallel resonator and the third capacitor 620 connected in series is connected in parallel with the fourth capacitor 630 and then connected in parallel with the ladder network as a whole.

Optionally, the coupling portion 150 may be in the form of a coupling boss or a coupling base, may be located directly below the branch 210 , and may be spaced from the branch 210 and coupled to form the fourth capacitor 630 .

It should be noted that, for the electrical connection relationship between the series arm, the first capacitor 500 , the third capacitor 620 , the fourth capacitor 630 and the LC parallel resonator of the low-pass band-stop filter module in the above-mentioned embodiment, please refer to the low-pass filter module above. The band-stop filter circuit will not be repeated here.

In the low-pass band-stop filter module 10 of the above-mentioned embodiment, the low-pass band-stop filter circuit can not only achieve the near-pass band suppression requirement theoretically, but also can realize physical design in actual processing, and the processing is simple and convenient. At the same time, it can take into account the characteristics of ultra-wideband and strong suppression of near-passband. Moreover, in the case of achieving the same difficulty index, it is beneficial to reduce the volume and lower the cost. In addition, each capacitive element is realized by using the tape conductors (the first tape conductor 200 and the second tape conductor 300 ), and the structure is simple and reliable, with high stability and good consistency.

As shown in FIG. 9 , optionally, a partition wall 160 is provided on the inner side wall of the communication groove 130 . In this way, each resonant cavity 120 is communicated with the communication slot 130 through the installation slot 110, and the mutual coupling between the resonant cavities 120 can be weakened by the partition wall 160, and the out-of-band suppression of the entire low-pass band-stop filter can be improved.

Wherein, the partition wall 160 can be integrally formed with the conductive cavity 100, which is convenient for processing.

Wherein, the number of the resonant cavity 120 can be flexibly designed or adjusted according to actual use requirements.

Optionally, there are at least two resonant cavities 120 , and at least two resonant cavities 120 are distributed on the same side of the installation slot 110 . In this way, the space on the side of the installation slot 110 can be fully utilized, and the volume of the low-pass band-rejection filter module 10 can be effectively reduced, which is beneficial to the development trend of miniaturization.

Optionally, there are at least two resonant cavities 120 , and the at least two resonant cavities 120 are staggered and distributed on opposite sides of the installation slot 110 . In this way, the space on both sides of the installation groove 110 can be utilized, which is beneficial to the arrangement of the first tape guide member 200 and the second tape guide member 300 .

As shown in FIG. 5 , FIG. 6 and FIG. 9 , specifically, there are five resonant cavities 120 , among which three resonant cavities 120 are distributed on the upper side of the installation groove 110 , and the other two resonant cavities 120 are distributed on the lower side of the installation groove 110 . The five resonant cavities 120 are arranged at intervals along the length direction of the first tape guide member 200 , and each resonant cavity 120 communicates with the installation groove 110 through the communication groove 130 .

In order to facilitate signal transmission, as shown in FIG. 5 and FIG. 6 , optionally, the low-pass band-stop filtering module 10 further includes an input connector 170 and an output connector 180 . In addition, the input connector 170 and the output connector 180 are electrically connected to opposite ends of the first tape guide 200 respectively. In this way, the signal is input from the input connector 170 , and after passing through various components of the low-pass band-stop filtering module 10 , the useless signal is suppressed to the maximum extent, so that the useful signal is output from the output connector 180 .

The input connector 170 and the output connector 180 may be provided on the left and right sides of the conductive cavity 100 respectively. Of course, the positions of the output connector 180 and the input connector 170 may be interchanged as required.

In order to ensure stable and reliable installation and fixation of the first tape guide member 200 and the second tape guide member 300 in the conductive cavity 100 . As shown in FIG. 5 , optionally, the low-pass band-stop filter module 10 further includes an insulating support member 190 . In this way, the insulating support 190 can be used to support the installation and fixation of the first tape guide 200 in the installation groove 110 , and the insulating support 190 can also be used to support the installation and fixation of the second tape guide 300 in the resonant cavity 120 . , to ensure that both the first tape guide member 200 and the second tape guide member 300 can be installed in accurate positions, thereby forming an accurate electrical structure.

The insulating support member 190 may be in the form of a support column or a support bar, and may be made of insulating materials such as polytetrafluoroethylene. One end of the insulating support member 190 may be plug-fitted with the bottom wall of the conductive cavity 100 , and the other end may be in contact with or adhered to the first tape guide member 200 or the second tape guide member 300 .

In one embodiment, a low-pass band-stop filter is provided, which is designed using the low-pass band-stop filter circuit of any of the foregoing embodiments; and/or the low-pass band-stop filter module of any of the foregoing embodiments is used 10.

The low-pass band-stop filter of the above-mentioned embodiment, its low-pass band-stop filter circuit can not only theoretically achieve the near-pass band suppression requirement, but also the low-pass band-stop filter module 10 can realize physical design from actual processing, and the processing is simple, convenient. At the same time, it can take into account the characteristics of ultra-wideband and strong suppression of near-passband. Moreover, in the case of achieving the same difficulty index, it is beneficial to reduce the volume and lower the cost. In addition, each capacitive element is realized by using the conduction band, the structure is simple and reliable, the stability is high, and the consistency is good.

In addition, in the actual production process, in order to achieve the required size of the capacitor in the low-pass band-stop filter circuit, in the production or design process, various parameters of the corresponding components can be adjusted to achieve the required size of the capacitor.

In one embodiment, a tuning method applied to the low-pass band-stop filtering module 10 of any of the above embodiments is also provided.

The size of the third capacitor 620 can be adjusted by adjusting the coupling degree between the branch 210 and the second tape conduction member 300 . In this way, the coupling degree between the branch 210 and the second tape conduction member 300 can be adjusted according to actual use requirements, so that the size of the third capacitor 620 can meet the use requirements.

Specifically, the coupling degree can be adjusted by adjusting the distance between the branch 210 and the second tape guide member 300; the size of the surface area of the branch 210 or the surface area of the second tape guide member 300 can also be adjusted independently, Or adjust the size of the surface area of the branch 210 and the size of the surface area of the second tape guide member 300 at the same time, so as to realize the adjustment of the coupling degree.

The size of the fourth capacitor 630 can be adjusted by adjusting the coupling degree between the coupling part 150 and the branch 210 . In this way, the coupling degree between the branch 210 and the coupling part 150 can be adjusted according to actual use requirements, so that the size of the fourth capacitor 630 can meet the use requirements.

Specifically, the coupling degree can be adjusted by adjusting the distance between the branch 210 and the coupling part 150 ; the size of the surface area of the branch 210 can also be adjusted independently, or the surface area of the coupling part 150 can be adjusted independently, or the size of the branch 210 can be adjusted simultaneously. The size of the surface area and the size of the surface area of the coupling part 150 can adjust the coupling degree.

The parameters of the LC parallel resonator can be adjusted by adjusting the coupling degree between the cover body 400 and the resonant column 140 . In this way, the coupling degree between the cover body 400 and the resonant column 140 can be adjusted according to actual use requirements, so that the size of the capacitive element formed by the equivalent spacing between the cover plate and the top of the resonance column 140 can meet the use requirements.

Specifically, the coupling degree can be adjusted by adjusting the distance between the cover body 400 and the resonant column 140; it is also possible to set an adjustment screw on the cover body 400, set an adjustment hole on the resonance column 140, and use the adjustment screw to extend into the adjustment hole The inner length realizes the adjustment of the coupling degree.

It should be noted that "a certain body" and "a certain part" can be a part of the corresponding "component", that is, "a certain body", "a certain part" and the "other parts of the component" are integrally formed; "Other parts" of a separate component, that is, "a body" and "a part" can be manufactured independently, and then combined with "other parts of the component" to form a whole. The expression of the above-mentioned "some body" and "some part" in this application is only one of the embodiments, for the convenience of reading, rather than limiting the scope of protection of the application, as long as the above features are included and the functions are the same, it should be understood as This application is equivalent to the technical solution.

It should be noted that the components included in the "unit", "component", "mechanism" and "device" of the present application can also be combined flexibly, that is, modular production can be performed according to actual needs, so as to facilitate modular assembly. The division of the above-mentioned components in the present application is only one of the embodiments, for the convenience of reading, rather than limiting the scope of protection of the present application, as long as the above-mentioned components are included and have the same function, it should be understood as an equivalent technical solution of the present application.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Back, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device or Elements must have a particular orientation, be constructed and operate in a particular orientation and are therefore not to be construed as limitations of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

It should be noted that when an element is referred to as being "fixed on", "disposed on", "fixed on" or "mounted on" another element, it can be directly on the other element or an intervening element may also be present . When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Further, when one element is considered to be a "fixed transmission connection" to another element, the two can be fixed in a detachable connection, or can be fixed in a non-detachable connection, as long as power transmission can be achieved, such as socket connection, snap connection. , integral molding fixing, welding, etc., can be realized in the prior art, and will not be redundant here. When a component and another component are perpendicular or approximately perpendicular to each other, it means that the ideal state of the two is vertical, but due to the influence of manufacturing and assembly, there may be a certain vertical error. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should also be understood that, when interpreting the connection relationship or positional relationship of elements, although not explicitly described, the connection relationship and positional relationship are interpreted as including a margin of error, which should be acceptable for a specific value determined by those skilled in the art. within the deviation range. For example, "about", "approximately" or "substantially" can mean within one or more standard deviations, without limitation.

The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, all It is considered to be the range described in this specification.

The above examples only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (14)

1. a low-pass band-stop filter circuit, characterized in that, comprising a series arm and a parallel arm; The parallel arm includes a three-device resonance unit; The series arm includes N first inductances connected in series between the input terminal and the output terminal; wherein, the connection node between the i-th first inductance and the (i+1)-th first inductance passes through the three The device resonance unit is connected to the ground terminal, and N is a positive integer greater than or equal to 2, i is a positive integer greater than or equal to 1, and i is less than N. 2 . The low-pass band-stop filter circuit according to claim 1 , wherein the parallel arm further comprises a first capacitor; wherein the (i+1)th first inductor and the (i+2)th first inductor The connection node between the first inductors is connected to the ground terminal through the first capacitor, and N is a positive integer greater than or equal to 3, i is a positive integer greater than or equal to 1, and i is less than N. 3 . The low-pass band-stop filter circuit according to claim 1 , wherein the three-device resonance unit comprises an LC series resonator and a second capacitor connected in parallel with the LC series resonator. 4 . 4 . The low-pass band-stop filter circuit according to claim 1 , wherein the three-device resonance unit comprises a three-device resonance equivalent circuit. 5 . 5 . The low-pass band-stop filter circuit according to claim 4 , wherein the three-device resonance equivalent circuit comprises an LC parallel resonator, a third capacitor connected in series with the LC parallel resonator, and a third capacitor connected in series with the LC parallel resonator. 6 . The third capacitor is connected in parallel with the fourth capacitor in the series structure of the LC parallel resonator. 6. A low-pass band-stop filter circuit, comprising a series arm and a parallel arm; the parallel arm includes a fifth capacitor; The series arm includes M first series units and H second series units connected in series between the input terminal and the output terminal, and the M first series units and the H second series units are alternately arranged, Wherein, the first series unit includes a three-device resonant unit for avoiding negative value inductance on the series arm, and the second series unit includes a second inductance; or, the first series unit includes a second inductance , the second series unit includes a three-device resonance unit for avoiding negative inductance on the series arm, and M and H are both positive integers greater than 1; Wherein, the connection node between the first series unit and the second series unit is connected to the ground terminal through the fifth capacitor. 7 . The low-pass band-stop filter circuit according to claim 6 , wherein the three-device resonance unit comprises a third inductor and an LC parallel resonator connected in series with the third inductor. 8 . 8. a kind of low-pass band-stop filter module adopting the low-pass band-stop filter circuit as claimed in claim 5, is characterized in that, comprises: A conductive cavity, the conductive cavity is provided with an installation slot, a resonant cavity arranged on the side of the installation slot, a communication slot for connecting the installation slot and the resonant cavity, and a resonant cavity arranged in the resonant cavity the resonant column; a first tape guide member, the first tape guide member is disposed in the installation groove and used to form the series arm and the first capacitor, and the first tape guide member is provided with a branch extending toward the communication groove; a second band-conducting element, one end of the second band-conducting element is electrically connected to the resonant column, and the other end of the second band-conducting element is coupled with the branch to form the third capacitor; and a cover body, the cover body is covered above the conductive cavity, the cover body is spaced apart from the resonant column and cooperates with the resonant column to form the LC parallel resonator; Wherein, the conductive cavity is further provided with a coupling portion, and the coupling portion can be coupled and matched with the branch to form the fourth capacitor. 9 . The low-pass band-stop filter module according to claim 8 , wherein the inner side wall of the communication groove is provided with a partition wall. 10 . 10 . The low-pass band-stop filter module according to claim 8 , wherein there are at least two resonant cavities, and at least two of the resonant cavities are distributed on the same side of the installation slot, or at least two Each of the resonant cavities are distributed on opposite sides of the installation slot. 11. The low-pass band-stop filter module according to claim 8, wherein the low-pass band-stop filter module further comprises an input connector and an output connector, and the input connector and the output connector are respectively connected with the The opposite ends of the first tape conducting member are electrically connected. 12. The low-pass band-stop filter module according to any one of claims 8 to 11, wherein the low-pass band-stop filter module further comprises an insulating support, the insulating support is used to support the first a tape guide and/or the second tape guide. 13. A low-pass band-stop filter, characterized in that it is designed using the low-pass band-stop filter circuit according to any one of claims 1 to 7; and/or adopts any one of claims 8 to 12 The low-pass band-stop filtering module described in item. 14. A tuning method applied to the low-pass band-rejection filter module according to any one of claims 8 to 12, characterized in that, by adjusting the coupling degree of the branch and the second band-conducting member to adjust all the the size of the third capacitor; and/or by adjusting the degree of coupling between the coupling portion and the branch to adjust the size of the fourth capacitor; and/or by adjusting the degree of coupling between the cover and the resonant column to adjust the parameters of the LC parallel resonator.

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