CN110429363A - A kind of three passband function filter-dividers based on multimode fork-shaped resonator - Google Patents

Abstract

The invention discloses a three-pass band power dividing filter based on a multi-mode fork-shaped resonator, which comprises a dielectric substrate, a metal grounding plate is provided on the bottom surface of the dielectric substrate, and an input port feeder, a first output feeder and a second feeder are provided on the top surface. The output feeder, the input port feeder is located in the middle of the dielectric substrate, the first output feeder and the second output feeder are respectively symmetrically arranged on both sides of the input port feeder; the input port feeder and the first output feeder are respectively provided with a first fork A three-mode fork resonator and a second fork-shaped three-mode resonator; a third fork-shaped three-mode resonator and a fourth fork-shaped three-mode resonator are respectively arranged between the input port feeder and the second output feeder.

Description

A Three-pass Band Power Divider Filter Based on Multimode Fork Resonator

technical field

The invention relates to the technical field of microwave passive devices, in particular to a three-pass band power dividing filter based on a multimode fork resonator.

Background technique

In modern wireless communication systems, power dividers and filters are important RF front-end passive components. In order to realize power distribution and filtering functions at the same time, they are often designed in the circuit in a cascaded manner. In this way, not only the circuit The volume will increase, and the circuit performance will decrease. Therefore, in order to reduce the size of the circuit and improve the performance of the circuit, the research of the power divider with filter response has been explored in recent years. At the same time, with the continuous development of modern wireless communication systems, the demand for multi-passband communication systems is also increased.

Document 1 [K.J.Song, M.Y.Fan, and F.Zhang, "Compact Triple-Band Power DividerIntegrated Bandpass-Filtering Response Using Short-Circuited SIRs," IEEE Trans.Compon.Packag.Manufact.Technol., vol.7, no. 7, July.2017] By utilizing a coupled short-circuit ladder impedance resonator and a half-wavelength resonator to achieve a three-passband filter response, three required passbands can be simultaneously obtained by adjusting the impedance ratio and electrical length. However, due to the complex circuit structure and high port isolation, the problem of poor out-of-band rejection affects the wide application of the power divider filter.

Literature 2 [C.-F.Chen, T.-Y.Huang, and R.-B.Wu, "Novel compact net-typeresonators and their applications to microstrip bandpass filters," IEEETrans.Microw.Theory Techn., vol. 54, no.2, pp.755-762, Feb.2006] By using a mesh three-mode resonator, a multi-passband microstrip filter is realized simply and efficiently without significantly increasing the circuit size , however, due to the limitation of the degree of freedom of the design parameters, it is difficult to realize the design requirements for all passbands at the same time, which increases the difficulty of the realization of the design.

Document 3 [R.Gómez-Garcia, R.Loeches-Sanchez, D.Psychogiou, and D.Peroulis, "Single/multi-band Wilkinson-type power dividers with embedded transversalfiltering sections and application to channelized filters," IEEETrans.Circuits Syst .I, Reg.Papers, vol.62, no.6, pp.1518-1527, Jun.2015.] proposed a new type of single/multiple passband Wilkinson power splitter with inherent filtering capability, but its The circuit is bulky and the port isolation is not good.

Contents of the invention

Purpose of the invention: The technical problem to be solved by the present invention is to provide a three-pass band power divider filter based on a multi-mode fork resonator for the deficiencies of the prior art.

In order to solve the above-mentioned technical problems, the present invention discloses a three-pass band power dividing filter based on a multi-mode fork resonator, which includes a dielectric substrate, a metal ground plate is provided on the bottom surface of the dielectric substrate, and an input port feeder is provided on the top surface. An output feeder and a second output feeder, the input port feeder is located in the middle of the dielectric substrate, the first output feeder and the second output feeder are symmetrically arranged on both sides of the input port feeder;

A first fork-shaped three-mode resonator and a second fork-shaped three-mode resonator are respectively arranged between the input port feeder and the first output feeder;

A third fork-shaped three-mode resonator and a fourth fork-shaped three-mode resonator are respectively arranged between the input port feeder and the second output feeder.

In the present invention, the input port feeder includes a first 50-ohm microstrip line conduction strip and an input coupling line, one end of the first 50-ohm microstrip line conduction strip is close to the first side of the dielectric substrate, and the other end is connected to the input coupling line; The connection between a 50-ohm microstrip line conduction tape and the first side of the dielectric substrate is the input end.

In the present invention, the first output feeder line is composed of a second 50-ohm microstrip line conduction band and an L-shaped output coupling line, the second 50-ohm microstrip line conduction band is close to the second side of the dielectric substrate, and the L-shaped output coupling line It is connected with the conduction band of the second 50 ohm microstrip line, the L-shaped output coupling line is parallel to the input coupling line, and the conduction band of the second 50 ohm microstrip line is perpendicular to the input coupling line;

The connection between the conduction tape of the 50 ohm microstrip line and the second side of the dielectric substrate is the first output end.

In the present invention, the second output feeder line is composed of a third 50-ohm microstrip line conduction band and an L-shaped output coupling line, the third 50-ohm microstrip line conduction band is close to the third side of the dielectric substrate, and the L-shaped output coupling line It is connected with the conduction band of the third 50 ohm microstrip line, the L-shaped output coupling line is parallel to the input coupling line, and the third 50 ohm microstrip line conduction band is perpendicular to the input coupling line;

The connection between the conduction tape of the 50 ohm microstrip line and the third side of the dielectric substrate is the third output end.

In the present invention, the first fork-shaped three-mode resonator includes a first terminal short-circuit stub, a first terminal open-circuit stub, a second terminal open-circuit stub, a first fork-shaped terminal open-circuit stub, and a first grounding post;

One end of the first grounding post is connected to the short-circuit stub end of the first terminal, and the other end is connected to the metal grounding plate through the dielectric substrate;

The first terminal open-circuit stub and the second terminal open-circuit stub are symmetrically arranged on both sides of the first terminal short-circuit stub;

The first fork-shaped terminal open-circuit branch and the first terminal short-circuit branch are on the same straight line, and both sides of the first fork-shaped terminal open-circuit branch are respectively symmetrically provided with a first L-shaped terminal open-circuit branch and a second L-shaped terminal open-circuit branch.

In the present invention, the second fork-shaped three-mode resonator includes a second terminal short-circuit stub, a third terminal open-circuit stub, a fourth terminal open-circuit stub, a second fork-shaped terminal open-circuit stub, and a second grounding column;

One end of the second grounding column is connected to the short-circuit stub of the second terminal, and the other end is connected to the metal grounding plate through the dielectric substrate;

The open-circuit stub of the third terminal and the open-circuit stub of the fourth terminal are respectively arranged symmetrically on both sides of the short-circuit stub of the second terminal;

The second fork-shaped terminal open-circuit branch and the second terminal short-circuit branch are on the same straight line, and the two sides of the second fork-shaped terminal open-circuit branch are respectively symmetrically provided with a third L-shaped terminal open-circuit branch and a fourth L-shaped terminal open-circuit branch.

In the present invention, the third fork-shaped three-mode resonator includes a third terminal short-circuit stub, a fifth terminal open-circuit stub, a sixth terminal open-circuit stub, a third fork-shaped terminal open-circuit stub, and a third grounding column;

One end of the third grounding column is connected to the short-circuit branch of the third terminal, and the other end is connected to the metal grounding plate through the dielectric substrate;

The fifth terminal open-circuit stub and the sixth terminal open-circuit stub are arranged symmetrically on both sides of the third terminal short-circuit stub;

The third fork-shaped terminal open-circuit branch and the third terminal short-circuit branch are on the same straight line, and both sides of the third fork-shaped terminal open-circuit branch are respectively symmetrically provided with a fifth L-shaped terminal open-circuit branch and a sixth L-shaped terminal open-circuit branch.

In the present invention, the fourth fork-shaped three-mode resonator includes a fourth terminal short-circuit stub, a seventh terminal open-circuit stub, an eighth terminal open-circuit stub, a fourth fork-shaped terminal open-circuit stub, and a fourth grounding column;

One end of the fourth grounding column is connected to the short-circuit stub of the fourth terminal, and the other end is connected to the metal grounding plate through the dielectric substrate;

The seventh terminal open-circuit stub and the eighth terminal open-circuit stub are symmetrically arranged on both sides of the fourth terminal short-circuit stub;

The fourth fork-shaped terminal open-circuit branch and the fourth terminal short-circuit branch are on the same straight line, and both sides of the fourth fork-shaped terminal open-circuit branch are respectively symmetrically provided with a seventh L-shaped terminal open-circuit branch and an eighth L-shaped terminal open-circuit branch.

In the present invention, the first fork-shaped three-mode resonator and the third fork-shaped three-mode resonator are symmetrical on both sides of the input coupling line; the second fork-shaped three-mode resonator and the fourth fork-shaped three-mode resonator are on the input coupling line symmetrical on both sides;

The first fork-shaped three-mode resonator and the fourth fork-shaped three-mode resonator are centrally symmetrically arranged;

The third fork-shaped three-mode resonator and the second fork-shaped three-mode resonator are center-symmetrically arranged.

The arrangement of the input port feeder, the first output feeder, the second output feeder and four fork-shaped three-mode resonators in the present invention has a compact structure, can be realized on a single PCB, is convenient for processing and integration, and has low production cost.

The invention utilizes the electric field distribution characteristics of four fork-shaped three-mode resonators with the same structure and the main transmission line, and has high selectivity and multi-passband characteristics.

The invention utilizes the characteristic of coupling between a wavelength main transmission line and a resonator and generating a zero point by an open branch, and has good out-of-band suppression characteristics.

The power dividing filter of the invention utilizes the indirect isolation resistance between resonators, has good port isolation, and is suitable for modern wireless communication systems.

Beneficial effects: the present invention processes and corrodes the metal surfaces of the front and back of the circuit substrate through the printed circuit board manufacturing process, thereby forming the required metal pattern, which has a simple structure and can be realized on a single PCB board, which is convenient for processing Integrated, low production cost. At the same time, good power distribution characteristics and filtering characteristics are obtained by using multi-mode fork resonators and network topology, and good port isolation characteristics are obtained by skillfully connecting isolation resistors between resonators.

Description of drawings

The advantages of the above and/or other aspects of the present invention will become clearer as the present invention will be further described in detail in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a three-dimensional structural schematic diagram of a three-pass band power dividing filter based on a multi-mode fork resonator according to the present invention.

FIG. 2 is a front view of Embodiment 1. FIG.

3 is a schematic view of the structural dimensions of Embodiment 1.

FIG. 4 is an S-parameter simulation diagram of Embodiment 1.

FIG. 5 is an S-parameter simulation diagram of matching characteristics and isolation characteristics of two output ports in Embodiment 1. FIG.

Fig. 6 is the second S-parameter simulation diagram of embodiment 1.

In the figure, the input port feeder 1, the first output feeder 2, the second output feeder 3, the first fork-shaped three-mode resonator 4, the second fork-shaped three-mode resonator 5, the third fork-shaped three-mode resonator 6, A fourth fork-shaped three-mode resonator 7, a metal ground plate 8, a rectangular dielectric substrate 9, a first isolation resistor R ₁ , and a second isolation resistor R ₂ .

Detailed ways

Embodiment, as shown in Fig. 1, the present embodiment provides a kind of three-pass band power divider filter based on the multimode fork resonator, comprising a dielectric substrate 9, the bottom surface of the dielectric substrate 9 is provided with a metal ground plate 8, and the top surface is provided with The input port feeder 1, the first output feeder 2 and the second output feeder 3, the input port feeder 1 is located in the middle of the dielectric substrate 9, the first output feeder 2 and the second output feeder 3 are arranged symmetrically on both sides of the input port feeder 1 respectively ;

A first fork-shaped three-mode resonator 4 and a second fork-shaped three-mode resonator 6 are respectively provided between the input port feeder 1 and the first output feeder 2;

A third fork-shaped three-mode resonator 5 and a fourth fork-shaped three-mode resonator 7 are respectively provided between the input port feeder 1 and the second output feeder 3 .

The input port feeder 1 includes a first 50-ohm microstrip line conduction strip 11 and an input coupling line 12, one end of the first 50-ohm microstrip line conduction strip 11 is close to the first side 9a of the dielectric substrate 9, and the other end is connected to the input coupling line 12; The connection between the first 50-ohm microstrip line conduction strip 11 and the first side of the dielectric substrate 9 is the input end.

The first output feeder 2 is composed of a second 50-ohm microstrip conduction strip 21 and an L-shaped output coupling line 22, the second 50-ohm microstrip conduction strip 21 is close to the second side 9b of the dielectric substrate 9, and the L-shaped output coupling line 22 is connected to the second 50 ohm microstrip line conduction band 21, the L-shaped output coupling line 22 is parallel to the input coupling line 12, and the second 50 ohm microstrip line conduction band 21 is perpendicular to the input coupling line 12;

The connection between the conduction strip 21 of the 50 ohm microstrip line and the second side of the dielectric substrate 9 is the first output end.

4. A kind of three-pass band power divider filter based on multimode fork resonator according to claim 1, characterized in that, the second output feeder 3 is coupled by the third 50 ohm microstrip line conduction band 31 and L-shaped output line 32, the third 50-ohm microstrip conduction band 31 is close to the third side 9c of the dielectric substrate 9, the L-shaped output coupling line 32 is connected to the third 50-ohm microstrip conduction band 31, and the L-shaped output coupling line 32 is connected to the third 50-ohm microstrip conduction band 31. The input coupling line 12 is parallel, and the third 50-ohm microstrip line conduction band 31 is perpendicular to the input coupling line 12;

The connection between the conduction tape 31 of the 50 ohm microstrip line and the third side of the dielectric substrate 9 is the third output end.

The first fork-shaped three-mode resonator 4 includes a first terminal short-circuit stub 41 , a first terminal open-circuit stub 42 , a second terminal open-circuit stub 43 , a first fork-shaped terminal open-circuit stub 44 and a first grounding post 47;

One end of the first grounding column 47 is connected to the end of the first terminal short-circuit stub 41 , and the other end is connected to the metal grounding plate 8 through the dielectric substrate 9 ;

The first terminal open-circuit stub 42 and the second terminal open-circuit stub 43 are arranged symmetrically on both sides of the first terminal short-circuit stub 41, respectively;

The first fork-shaped terminal open-circuit branch 44 and the first terminal short-circuit branch 41 are on the same straight line, and the two sides of the first fork-shaped terminal open-circuit branch 44 are respectively symmetrically provided with a first L-shaped terminal open-circuit branch 45 and a second L-shaped terminal open-circuit branch. 46.

The second fork-shaped three-mode resonator 5 includes a second terminal short-circuit stub 51 , a third terminal open-circuit stub 52 , a fourth terminal open-circuit stub 53 , a second fork-shaped terminal open-circuit stub 54 and a second grounding post 57;

One end of the second grounding column 57 is connected to the second terminal short-circuit stub 51 , and the other end is connected to the metal grounding plate 8 through the dielectric substrate 9 ;

The third terminal open-circuit stub 52 and the fourth terminal open-circuit stub 53 are arranged symmetrically on both sides of the second terminal short-circuit stub 51, respectively;

The second fork-shaped terminal open-circuit branch 54 and the second terminal short-circuit branch 51 are on the same straight line, and the two sides of the second fork-shaped terminal open-circuit branch 54 are respectively symmetrically provided with a third L-shaped terminal open-circuit branch 55 and a fourth L-shaped terminal open-circuit branch. 56.

The third fork-shaped three-mode resonator 6 includes a third terminal short-circuit stub 61 , a fifth terminal open-circuit stub 62 , a sixth terminal open-circuit stub 63 , a third fork-shaped terminal open-circuit stub 64 and a third grounding post 67;

One end of the third grounding column 67 is connected to the third terminal short-circuit stub 61 , and the other end is connected to the metal grounding plate 8 through the dielectric substrate 9 ;

The fifth terminal open-circuit branch 62 and the sixth terminal open-circuit branch 63 are arranged symmetrically on both sides of the third terminal short-circuit branch 61, respectively;

The third fork-shaped terminal open-circuit branch 64 and the third terminal short-circuit branch 61 are on the same straight line, and the two sides of the third fork-shaped terminal open-circuit branch 64 are respectively symmetrically provided with a fifth L-shaped terminal open-circuit branch 65 and a sixth L-shaped terminal open-circuit branch. 66.

The fourth fork-shaped three-mode resonator 7 includes a fourth terminal short-circuit stub 71, a seventh terminal open-circuit stub 72, an eighth terminal open-circuit stub 73, a fourth fork-shaped terminal open-circuit stub 74, and a fourth grounding post 77;

One end of the fourth grounding post 77 is connected to the fourth terminal short-circuit stub 71 , and the other end is connected to the metal grounding plate 8 through the dielectric substrate 9 ;

The seventh terminal open-circuit branch 72 and the eighth terminal open-circuit branch 73 are arranged symmetrically on both sides of the fourth terminal short-circuit branch 71;

The fourth fork-shaped terminal open-circuit branch 74 and the fourth terminal short-circuit branch 71 are on the same straight line, and both sides of the fourth fork-shaped terminal open-circuit branch 74 are respectively symmetrically provided with a seventh L-shaped terminal open-circuit branch 75 and an eighth L-shaped terminal open-circuit branch 76.

The first fork-shaped three-mode resonator 4 and the third fork-shaped three-mode resonator 5 are symmetrical on both sides of the input coupling line 12;

The second fork-shaped three-mode resonator 6 and the fourth fork-shaped three-mode resonator 7 are symmetrical on both sides of the input coupling line 12;

The first fork-shaped three-mode resonator 4 and the fourth fork-shaped three-mode resonator 7 are center-symmetrically arranged;

The third fork-shaped three-mode resonator 5 and the second fork-shaped three-mode resonator 6 are arranged symmetrically about the center.

The front view is shown in Figure 2, and the relevant dimensions are shown in Figure 3. The dielectric substrate 7 used has a relative permittivity of 3.55, a thickness of 0.508 mm, and a loss tangent of 0.0027. With reference to Figure 3, the size parameters of the power division filter are as follows: W ₁ =0.21mm, W ₂ =0.42mm, W ₃ =0.21mm, W ₄ =0.3mm, W ₅ =1.18mm, L ₁ =5mm, L ₂ = 1.41 mm, L ₃ = 2.987 mm, L ₄ = 12.44 mm, L ₅ = 9.95 mm, L ₆ = 7.81 mm, L ₇ = 3.473 mm, L ₈ = 9.7 mm, L ₉ = 1.67 mm, L ₁₀ = 1.9 mm, g ₁ =0.22 mm, g ₂ =0.18 mm, R ₁ =2500Ω, R ₂ =5000Ω.

The power dividing filter of this example is modeled and simulated in the electromagnetic simulation software HFSS.13.0. Figure 4 is the S-parameter simulation diagram of the power division filter in this example. It can be seen from the figure that the center frequencies of the three passbands of the three-pass band power division filter are 1.53GHz, 2.0GHz, and 2.36GHz. The 3dB relative bandwidths are 3.56%, 8.65%, and 2.75%, respectively, the return loss in the passband is lower than 18.4dB, and the minimum insertion loss is 1.2dB. There are five transmission zeros outside the passband, which makes the power division filter of this example have good frequency selectivity and out-of-band harmonic suppression.

Figure 5 is the S-parameter simulation diagram of the matching characteristics and isolation characteristics of the two power output ports of the power division filter in this example. It can be seen from the figure that the output port return loss in the passband of the power division filter in this example is low At 11.8dB, the in-band isolation is better than 15.7dB.

In manufacturing, the present invention processes and corrodes the metal surfaces of the front and back of the circuit substrate through a printed circuit board manufacturing process, thereby forming the required metal pattern, which has a simple structure and can be realized on a single PCB board, which is convenient for processing integration and production low cost. At the same time, good power distribution characteristics and filtering characteristics are obtained by using multi-mode fork resonators and network topology, and good port isolation characteristics are obtained by skillfully connecting isolation resistors between resonators.

Because the three-pass band power dividing filter of the present invention has high selectivity, compact structure, good port isolation and good out-of-band suppression characteristics, high selectivity, small insertion loss, and good out-of-band suppression performance, it is suitable for modern wireless communications system.

As shown in Figure 6, since the coupled line structure in this circuit structure can periodically generate zero points, it can achieve a good out-of-band suppression effect in a wider frequency band outside the passband.

This embodiment utilizes multi-mode fork resonators and network topology to obtain good power distribution characteristics and filtering characteristics, and ingeniously connects isolation resistors between resonators to obtain good port isolation characteristics to achieve a high selectivity, Compact structure, good port isolation and good out-of-band suppression characteristics, high selectivity, small insertion loss, and good out-of-band suppression performance three-pass power divider filter, suitable for modern wireless communication systems.

The present invention provides an idea and method of a three-pass band power dividing filter based on a multi-mode fork resonator. There are many methods and approaches to specifically realize the technical solution. The above is only a preferred embodiment of the present invention, and should be It is pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components that are not specified in this embodiment can be realized by existing technologies.

Claims (9)

1. a kind of three passband function filter-dividers based on multimode fork-shaped resonator, which is characterized in that including medium substrate (9), be situated between Matter substrate (9) bottom surface is equipped with metal ground plate (8), and top surface is equipped with input port feeder line (1), the first output feeder (2) and second Output feeder (3), input port feeder line (1) are located at the middle part of medium substrate (9), the first output feeder (2) and the second output feedback Line (3) is symmetrically arranged at the two sides of input port feeder line (1)；

Three mould resonator (4) of the first fork-shaped and are respectively equipped between the input port feeder line (1) and the first output feeder (2) Three mould resonator (6) of tree binary lorm；

Three mould resonator (5) of third fork-shaped and are respectively equipped between the input port feeder line (1) and the second output feeder (3) Four fork-shapeds, three mould resonator (7).

2. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that The input port feeder line (1) includes the one 50 ohm microstrip conduction band (11) and input coupling line (12), and the one 50 ohm micro- Band line conduction band (11) one end connects input coupling line (12) close to medium substrate (9) first side (9a), the other end；One 50 Europe Nurse microstrip line conduction band (11) and medium substrate (9) first side junction are input terminal.

3. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that First output feeder (2) is made of the 2nd 50 ohm microstrip conduction band (21) and L shape output coupling line (22), the 2nd 50 Europe Nurse microstrip line conduction band (21) is close to medium substrate (9) second side (9b), L shape output coupling line (22) and the 2nd 50 ohm microstrip Line conduction band (21) connection, L shape output coupling line (22) is parallel with input coupling line (12), the 2nd 50 ohm microstrip conduction band (21) It is vertical with input coupling line (12)；

50 ohm microstrip conduction bands (21) and 9 second side junction of medium substrate are the first output end.

4. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that Second output feeder (3) is made of the 3rd 50 ohm microstrip conduction band (31) and L shape output coupling line (32), the 3rd 50 Europe Nurse microstrip line conduction band (31) is close to medium substrate (9) third side (9c), L shape output coupling line (32) and the 3rd 50 ohm microstrip Line conduction band (31) connection, L shape output coupling line (32) is parallel with input coupling line (12), the 3rd 50 ohm microstrip conduction band (31) It is vertical with input coupling line (12)；

50 ohm microstrip conduction bands (31) and medium substrate (9) third side junction are third output end.

5. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that First fork-shaped, three mould resonator (4) includes first terminal short circuit minor matters (41), first terminal is opened a way minor matters (42), second terminal is opened Road minor matters (43), the first fork-shaped open-end minor matters (44) and the first earthing rod (47)；

First earthing rod (47) one end connects first terminal short circuit minor matters (41) end, and the other end is connected across medium substrate (9) To metal ground plate (8)；

First terminal open circuit minor matters (42) and second terminal open circuit minor matters (43) are symmetrically arranged at first terminal short circuit minor matters (41) two sides；

First fork-shaped open-end minor matters (44) and first terminal short circuit minor matters (41) are in same straight line, the first fork-shaped open-end The two sides of minor matters (44) are respectively symmetrically equipped with the first L shape open-end minor matters (45) and the 2nd L shape open-end minor matters (46).

6. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that Second fork-shaped, three mould resonator (5) includes second terminal short circuit minor matters (51), third terminal is opened a way minor matters (52), the 4th terminal is opened Road minor matters (53), the second fork-shaped open-end minor matters (54) and the second earthing rod (57)；

Second earthing rod (57) one end connects second terminal short circuit minor matters (51), and the other end passes through medium substrate (9) and is connected to gold Belong to earth plate (8)；

Third terminal open circuit minor matters (52) and the 4th open-end minor matters (53) are symmetrically arranged at second terminal short circuit minor matters (51) two sides；

Second fork-shaped open-end minor matters (54) and second terminal short circuit minor matters (51) are in same straight line, the second fork-shaped open-end The two sides of minor matters (54) are respectively symmetrically equipped with the 3rd L shape open-end minor matters (55) and the 4th L shape open-end minor matters (56).

7. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that Three mould resonator (6) of third fork-shaped includes that third terminal short circuit minor matters (61), the 5th open-end minor matters (62), the 6th terminal are opened Road minor matters (63), third fork-shaped open-end minor matters (64) and third earthing rod (67)；

Third earthing rod (67) one end connects third terminal short circuit minor matters (61), and the other end passes through medium substrate (9) and is connected to gold Belong to earth plate (8)；

5th open-end minor matters (62) and the 6th open-end minor matters (63) are symmetrically arranged at third terminal short circuit minor matters (61) two sides；

Third fork-shaped open-end minor matters (64) and third terminal short circuit minor matters (61) are in same straight line, third fork-shaped open-end The two sides of minor matters (64) are respectively symmetrically equipped with the 5th L shape open-end minor matters (65) and the 6th L shape open-end minor matters (66).

8. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 1, which is characterized in that 4th fork-shaped, the three mould resonator (7) includes the 4th terminal short circuit minor matters (71), the 7th open-end minor matters (72), the 8th end End open circuit minor matters (73), the 4th fork-shaped open-end minor matters (74) and the 4th earthing rod (77)；

4th earthing rod (77) one end connects the 4th terminal short circuit minor matters (71), and the other end passes through medium substrate (9) and is connected to gold Belong to earth plate (8)；

7th open-end minor matters (72) and the 8th open-end minor matters (73) are symmetrically arranged at the 4th terminal short circuit minor matters (71) two sides；

4th fork-shaped open-end minor matters (74) and the 4th terminal short circuit minor matters (71) are in same straight line, the 4th fork-shaped open-end The two sides of minor matters (74) are respectively symmetrically equipped with the 7th L shape open-end minor matters (75) and the 8th L shape open-end minor matters (76).

9. a kind of three passband function filter-dividers based on multimode fork-shaped resonator according to claim 2, which is characterized in that First fork-shaped, three mould resonator (4) and three mould resonator (5) of third fork-shaped are symmetrical in input coupling line (12) two sides；

Second fork-shaped, three mould resonator (6) and three mould resonator (7) of the 4th fork-shaped are symmetrical in input coupling line (12) two sides；

It is symmetrical arranged centered on first fork-shaped, three mould resonator (4) and three mould resonator (7) of the 4th fork-shaped；

It is symmetrical arranged centered on three mould resonator (6) of three mould resonator (5) of third fork-shaped and the second fork-shaped.