CN117937082A - High-power high-selectivity multi-coupling microwave assembly - Google Patents

Abstract

The invention provides a high-power high-selectivity multi-coupling microwave component, which belongs to the field of filtering power division coupling modules and comprises a filter, a ground layer, a dielectric substrate, a power divider and a coupler, wherein the filter and the dielectric substrate are made of aluminum oxide, a plurality of resonant cavities are identical in size and internally provided with blind holes, the resonant cavities are sequentially connected along a u-type or n-type path direction through coupling windows, a first feed probe is inserted into the resonant cavity positioned at one end of the u-type or n-type path, a second feed probe is inserted into the resonant cavity positioned at the other end of the u-type or n-type path, the input end and the output end of the power divider are respectively used as main coupling microstrip lines of the coupler, and the coupler is formed by the main coupling microstrip lines and the branch coupling microstrip lines; the filter, the power divider and the coupler are cascaded, the integration level is high, the alumina realizes high power, the power divider is a main coupling microstrip line, the coupler is formed by the power divider and a branch coupling microstrip line, the multipath coupling output is realized, the distance between the branch coupling microstrip line and the branch of the power divider and the line width of the microstrip line are adjusted, and the couplers with different standards are realized.

Description

High-power high-selectivity multi-coupling microwave assembly

Technical Field

The invention relates to the technical field of filtering power division coupling modules, in particular to a high-power high-selectivity multi-coupling microwave assembly.

Background

With the development of radio frequency passive devices and the wide use of 5G, in order to achieve the goal of universal interconnection, higher requirements are put on radio frequency microwave modules related to signal transmission and communication base stations, so that the performance and the size of the radio frequency microwave modules need to be improved continuously, and the integration of various devices in the radio frequency front end is an object of important attention, so that the radio frequency front end will develop towards the direction of small integration and high performance.

In the prior art, a circuit of a power amplifier and a filter in a Chinese patent application of a filtering power amplifier antenna array module with publication number CN117317617A is arranged on a substrate, a feed probe led out of a resonant cavity penetrates through the substrate to be connected with a feed line-shaped successful divider feed and connected to an array antenna and radiate electromagnetic waves, the filter in the module is arranged into a symmetrical structure, the temperature stability of the filter is poor due to the fact that the filter performance of the symmetrical structure is very sensitive to temperature change, and the design flexibility of the filter is limited due to the fact that the symmetrical structure is difficult to realize very wide bandwidth, the filter and the substrate are made of Ferro-A6M materials, so that the module cannot be applied to a high-power scene, and multipath coupling output cannot be realized.

Disclosure of Invention

The technical problem to be solved by the invention is how to design a multi-coupling microwave component with high power, high integration level and high isolation level.

The invention solves the technical problems through the following technical scheme: the utility model provides a high-power high selectivity multi-coupling microwave subassembly, includes wave filter, ground plane, dielectric substrate, merit divides ware and coupler, the wave filter sets up the upper surface at the ground plane, the ground plane sets up the upper surface at dielectric substrate, merit divides the ware to set up the lower surface at dielectric substrate, wave filter and dielectric substrate material are the aluminium oxide, the wave filter includes a plurality of resonant cavities, and a plurality of resonant cavities size are the same and inside is provided with the blind hole, and blind hole radius is the same but the degree of depth is different, and a plurality of resonant cavities are connected gradually through the coupling window along u type or n type route direction, and the resonant cavity that is located one end of u type or n type route has inserted first feed probe, and the resonant cavity of the other end has inserted the second feed probe, and first feed probe is connected with the input microstrip line, and the merit divides the ware input and divide the output to be the main coupling line of coupler respectively, constitutes the coupler with the branch microstrip coupling line.

The high-performance filter, the power divider and the coupler are connected together through the cascade structure, the integration level is high, the size is small, the filter and the dielectric substrate are made of aluminum oxide, the aluminum oxide has high thermal conductivity, high-power requirements can be met, the structure of the filter is an asymmetric structure, insertion loss is effectively reduced, the filter has a better surface on the group delay characteristic, the asymmetric structure is designed more flexibly, one input end and two output ends of the power divider are respectively used as main coupling microstrip lines of the coupler, the coupler is formed by coupling the two input ends and the branch coupling microstrip lines, three couplers with different coupling coefficients can be obtained, multipath coupling output is realized, and therefore different coupling degrees can be achieved in one module. The coupling quantity of the coupler can be adjusted by adjusting the distance between the branch coupling microstrip line and the branch of the power divider and the line width of the microstrip line, so that couplers with different standards are realized, and the isolation degree among a plurality of couplers is high.

Preferably, the power divider comprises a first impedance converter, a second impedance converter and an isolation resistor, wherein the input end of the power divider is connected to the output end of the power divider through the first impedance converter and the second impedance converter respectively, and the isolation resistor is arranged at the inner side end of the first impedance converter and the inner side end of the second impedance converter, which are close to each other.

Preferably, the input end of the power divider is connected to the first output end of the power divider through a first impedance converter, the input end of the power divider is connected to the second output end of the power divider through a second impedance converter, the branch coupling microstrip line comprises a first branch coupling microstrip line, a second branch coupling microstrip line and a third branch coupling microstrip line, the input end of the power divider and the first branch coupling microstrip line form a first coupler, the first output end of the power divider and the second branch coupling microstrip line form a second coupler, and the second output end of the power divider and the third branch coupling microstrip line form a third coupler.

Preferably, the coupling degree of the first coupler is 8dB, the coupling degree of the second coupler is 16dB, and the coupling degree of the third coupler is 12dB.

Preferably, the blind hole is located at the center of the resonant cavity, the resonant cavities comprise a first resonant cavity, a second resonant cavity, a third resonant cavity, a fourth resonant cavity, a fifth resonant cavity and a sixth resonant cavity, the first resonant cavity is internally provided with a first blind hole, the second resonant cavity is internally provided with a second blind hole, the third resonant cavity is internally provided with a third blind hole, the fourth resonant cavity is internally provided with a fourth blind hole, the fifth resonant cavity is internally provided with a fifth blind hole, and the sixth resonant cavity is internally provided with a sixth blind hole.

Preferably, a first square groove or a first round hole is arranged between the first resonant cavity and the sixth resonant cavity to form inductive cross coupling, a second square groove or a second round hole is arranged between the second resonant cavity and the fifth resonant cavity to form capacitive cross coupling, and a transmission zero point is introduced.

Preferably, the first feed probe and the second feed probe are metal probes, the first feed probe extends and penetrates through the ground layer and the dielectric substrate to be connected to the input microstrip line, and the second feed probe extends and penetrates through the ground layer and the dielectric substrate to be connected to the input end of the power divider.

Preferably, the input microstrip line and the second feed probe are both added with a metal shielding cover, and the metal shielding cover is connected with the ground layer for blocking electromagnetic waves.

Preferably, the characteristic impedance of the input microstrip line is 50 ohms.

Preferably, the dielectric substrate has a relative permittivity of 9.8, a loss tangent of 0.00014, and a thickness of 1.524mm.

The invention provides the advantages that:

1. The high-performance filter, the power divider and the coupler are connected together through the cascade structure, the integration level is high, the size is small, the filter and the dielectric substrate are made of aluminum oxide, the aluminum oxide has high thermal conductivity, high-power requirements can be met, the structure of the filter is an asymmetric structure, insertion loss is effectively reduced, the filter has a better surface on the group delay characteristic, the asymmetric structure is designed more flexibly, one input end and two output ends of the power divider are respectively used as main coupling microstrip lines of the coupler, the coupler is formed by coupling the two input ends and the branch coupling microstrip lines, three couplers with different coupling coefficients can be obtained, multipath coupling output is realized, and therefore different coupling degrees can be achieved in one module. The coupling quantity of the coupler can be adjusted by adjusting the distance between the branch coupling microstrip line and the branch of the power divider and the line width of the microstrip line, so that couplers with different standards are realized, and the isolation degree among a plurality of couplers is high.

2. The blind holes are identical in radius and different in depth, the frequency points are finely adjusted by adjusting the depth of the blind holes, the adjustment of the depth of the blind holes is simple, and the depth of the blind holes can be directly adjusted by directly adjusting the depth of the rods on the premise of not changing the die.

3. The invention introduces a first square groove or a first round hole between the first resonant cavity and the sixth resonant cavity to form inductive cross coupling, introduces a second square groove or a second round hole between the second resonant cavity and the fifth resonant cavity to form capacitive cross coupling, thereby forming a transmission loop with a 180-degree phase difference of two loops, and introducing a transmission zero point to improve the passband selection characteristic of the filter.

Drawings

FIG. 1 is a schematic diagram of an explosion structure of a high-power high-selectivity multi-coupling microwave assembly according to an embodiment of the present invention;

FIG. 2 is a top view of a high power, high selectivity, multi-coupled microwave assembly provided by an embodiment of the present invention;

FIG. 3 is a front view of a high power, high selectivity, multi-coupled microwave assembly provided by an embodiment of the present invention;

FIG. 4 is an equivalent circuit diagram of a filter in a high-power high-selectivity multi-coupling microwave assembly according to an embodiment of the present invention;

FIG. 5 is a simulation diagram of the insertion loss and the isolation of the power divider of the high-power high-selectivity multi-coupling microwave assembly provided by the embodiment of the invention;

FIG. 6 is a simulation diagram of the coupling degree of a high-power high-selectivity multi-coupling microwave assembly provided by an embodiment of the invention;

FIG. 7 is a simulation diagram of isolation of a high-power high-selectivity multi-coupling microwave assembly according to an embodiment of the present invention;

FIG. 8 is a simulation diagram of isolation between coupling ends of different couplers of a high-power high-selectivity multi-coupling microwave assembly provided by an embodiment of the invention;

FIG. 9 is a schematic diagram of directivity of a high-power high-selectivity multi-coupling microwave assembly according to an embodiment of the present invention;

FIG. 10 is a diagram of thermal simulation results of a design of a high-power high-selectivity multi-coupling microwave assembly according to an embodiment of the present invention;

in the figure: a filter 10, a first feed probe 11, a second feed probe 12, a first resonant cavity 13, a first blind hole 131, a first coupling window 132, a first square groove 133, a second resonant cavity 14, a second blind hole 141, a second coupling window 142, a second square groove 143, a third resonant cavity 15, a third blind hole 151, a third coupling window 152, a fourth resonant cavity 16, a fourth blind hole 161, a fourth coupling window 162, a fifth resonant cavity 17, a fifth blind hole 171, a fifth coupling window 172, a sixth resonant cavity 18, a sixth blind hole 181, a ground layer 20, a 30 medium substrate, a 41 power divider input terminal, a 42 power divider output terminal, a first power divider output terminal 422, a second power divider output terminal 43, a second impedance transformer 44, a 45 isolation resistor, a 51 branch coupling line, a 511 first branch coupling microstrip line, a 512 second branch coupling line, a 513 third branch coupling line, a 60 microstrip input line, and a 70 metal shield.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1-3, this embodiment provides a high-power high-selectivity multi-coupling microwave assembly, including a filter 10, a ground layer 20, a dielectric substrate 30, a power divider and a coupler, where the filter 10 is disposed on the upper surface of the ground layer 20, the ground layer 20 is disposed on the upper surface of the dielectric substrate 30, the power divider is disposed on the lower surface of the dielectric substrate 30, the filter 10 and the dielectric substrate 30 are made of alumina, the filter 10 includes multiple resonant cavities, the multiple resonant cavities have the same size and are internally provided with blind holes, the blind holes have the same radius but different depths, the multiple resonant cavities are sequentially connected along the u-type or n-type path direction through coupling windows, the resonant cavity at one end of the u-type or n-type path is inserted with a first feed probe 11, the resonant cavity at the other end is inserted with a second feed probe 12, the first feed probe 11 is connected with an input microstrip line 60, the second feed probe 12 is connected with an input end 41 of the power divider, and the input end 41 and the output end 42 of the power divider are respectively used as a main coupling line of the coupler and a branch microstrip coupling line 51.

The high-performance filter 10, the power divider and the coupler are connected together through the cascade structure, the integration level is high, the size is small, the filter 10 and the dielectric substrate 30 are made of aluminum oxide, the aluminum oxide has high thermal conductivity, high-power requirements can be met, one input end and two output ends of the power divider are respectively used as main coupling microstrip lines of the coupler, the coupler is formed by the two output ends of the power divider and the branch coupling microstrip line 51, three couplers with different coupling coefficients can be obtained, multipath coupling output is achieved, and therefore different coupling degrees can be achieved in one module. The coupling amount of the coupler can be adjusted by adjusting the distance between the branch coupling microstrip line 51 and the branch of the power divider and the line width of the microstrip line, so that couplers with different standards are realized, and the isolation degree among a plurality of couplers is high.

Referring to fig. 1, the plurality of resonant cavities includes a first resonant cavity 13, a second resonant cavity 14, a third resonant cavity 15, a fourth resonant cavity 16, a fifth resonant cavity 17 and a sixth resonant cavity 18, a first blind hole 131 is provided in the first resonant cavity 13, a second blind hole 141 is provided in the second resonant cavity 14, a third blind hole 151 is provided in the third resonant cavity 15, a fourth blind hole 161 is provided in the fourth resonant cavity 16, a fifth blind hole 171 is provided in the fifth resonant cavity 17, and a sixth blind hole 181 is provided in the sixth resonant cavity 18.

The size of the plurality of resonant cavities is determined by the center frequency, and in actual operation, the resonant frequency can be determined according to eigenmode simulation, so that the size of the resonant cavities is determined. In this embodiment, the size of the resonant cavity may be set to 9.2mm in length, 9.2mm in width, and 9mm in height. The blind holes are arranged in the center of the resonant cavity, the radius of the blind holes has little influence on the TM10 mode, the radius of the blind holes is the same but the depth is different, in the embodiment, the radius of the blind holes is uniformly set to be 2.2mm, the fine adjustment of frequency points is carried out by adjusting the depth of the blind holes, the implementation of adjusting the depth of the blind holes is simple, and the depth of the blind holes can be directly adjusted on the premise that the die is not replaced.

In this embodiment, the depth of the first blind hole 131 is 3.73mm, the depth of the second blind hole 141 is 4.595mm, the depth of the third blind hole 151 is 4.595mm, the depth of the fourth blind hole 161 is 4.6mm, the depth of the fifth blind hole 171 is 4.59mm, and the depth of the sixth blind hole 181 is 3.79mm.

The first resonant cavity 13 is connected with the second resonant cavity 14 through a first coupling window 132, the second resonant cavity 14 is connected with the third resonant cavity 15 through a second coupling window 142, the third resonant cavity 15 is connected with the fourth resonant cavity 16 through a third coupling window 152, the fourth resonant cavity 16 is connected with the fifth resonant cavity 17 through a fourth coupling window 162, and the fifth resonant cavity 17 is connected with the sixth resonant cavity 18 through a fifth coupling window 172. The first, second, third, fourth and fifth coupling windows 132, 142, 152, 162, 172 have the same thickness and height, and have a thickness of 1.2mm and a height of 9mm. The adjustment of the amount of inductive coupling can be achieved by adjusting the width of the coupling windows, the width of the first coupling window 132 is 8.34mm, the width of the second coupling window 142 is 6.79mm, the width of the third coupling window 152 is 6.94mm, the width of the fourth coupling window 162 is 6.9mm, and the width of the fifth coupling window 172 is 8.36mm. The depth error may be 5 micrometers, and the other dimension error may be 10 micrometers. The overall size of the high-power high-selectivity multi-coupling microwave assembly of the invention can be set to 30×19.6× 10.724mm.

A first square groove or a first round hole is arranged between the first resonant cavity 13 and the sixth resonant cavity 18 to form inductive cross coupling, a second square groove or a second round hole is arranged between the second resonant cavity 14 and the fifth resonant cavity 17 to form capacitive cross coupling, and a transmission zero point is introduced. In this embodiment, the first square groove 133 is introduced between the first resonant cavity 13 and the sixth resonant cavity 18 to form inductive cross coupling, the second square groove 143 is introduced between the second resonant cavity 14 and the fifth resonant cavity 17 to form capacitive cross coupling, so as to form a transmission loop with a 180 ° phase difference of two loops, the transmission zero is introduced to improve the passband selection characteristic of the filter, the phase change of the signal transmission path is shown in table 1, and the equivalent circuit of the filter with double cross coupling is shown in fig. 4.

Table 1 filter signal transmission path phase variation

With continued reference to fig. 1, the first feed probe 11 and the second feed probe 12 are both metal probes, the first feed probe 11 extending through the ground layer 20 and the dielectric substrate 30 to be connected to the input microstrip line 60, and the second feed probe 12 extending through the ground layer 20 and the dielectric substrate 30 to be connected to the power divider input 41. The input microstrip line 60 and the second feed probe 12 are both added with a metal shielding cover 70, and the metal shielding cover 70 is connected with the ground layer 20 for blocking electromagnetic waves, so that in-band insertion loss is reduced, and out-of-band suppression is ensured. Specifically, a slot is formed in the dielectric substrate 30, a metal shielding cover is added in the slot, the second feed probe 12 is the output of the filter, a through hole is formed at the position where the second feed probe 12 penetrates through the dielectric substrate 30, and shielding units are arranged around the through hole. A circular anti-pad is provided at both the location where the first feed probe 11 penetrates the ground layer 20 and the location where the second feed probe 12 penetrates the ground layer 20.

The filter 10 is processed by adopting the HTCC process, and the defect that the traditional LTCC lamination processing mode is easy to generate misalignment can be avoided. The filter 10 is constructed in an asymmetric configuration (the depth of each resonator of the filter is different), the asymmetric configuration design can more easily achieve impedance matching with the input and output terminals, thereby reducing reflection and loss, the asymmetric design can provide a higher Q value, thereby reducing insertion loss, and the asymmetric configuration can excite specific resonant modes with lower loss, thereby helping to reduce overall insertion loss. The filter of the invention not only can effectively reduce the insertion loss, but also can make the filter have better performance on the group delay characteristic, and the design flexibility of the asymmetric structure is higher.

The characteristic impedance of the input microstrip line 60 is 50 ohms. The dielectric substrate 30 had a relative permittivity of 9.8, a loss tangent of 0.00014 and a thickness of 1.524mm. The thickness of the dielectric substrate 30 is 1.524mm, the dielectric substrate 30 is connected with a power divider at the bottom through an anti-bonding pad, the power divider can be a Wilkinson power divider, the power divider comprises a first impedance converter 43, a second impedance converter 44 and an isolation resistor 45, an input end 41 of the power divider is connected to an output end 42 of the power divider through the first impedance converter 43 and the second impedance converter 44 respectively, and the isolation resistor 45 is arranged at the inner side end, close to each other, of the first impedance converter 43 and the second impedance converter 44.

Specifically, the power divider input end 41 is connected to the first power divider output end 421 through the first impedance transformer 43, the power divider input end 41 is connected to the second power divider output end 422 through the second impedance transformer 44, the branch coupling microstrip line 51 includes a first branch coupling microstrip line 511, a second branch coupling microstrip line 512 and a third branch coupling microstrip line 513, the power divider input end 41 and the first branch coupling microstrip line 511 form a first coupler, the coupling degree of the first coupler is 8dB, the first power divider output end 421 and the second branch coupling microstrip line 512 form a second coupler, the coupling degree of the second coupler is 16dB, the second power divider output end 422 and the third branch coupling microstrip line 513 form a third coupler, and the coupling degree of the third coupler is 12dB. The coupling amount of the coupler can be adjusted by adjusting the distance between the branch coupling microstrip line 51 and the input end and the output end of the power divider and adjusting the line widths of the branch coupling microstrip line 51, the input end 41 and the output end 42 of the power divider.

The invention can balance two output ports of the power divider by arranging the isolation resistor 45 between the first impedance converter 43 and the second impedance converter 44, and has the isolation function, and if the circuit is open or short-circuited, the reflected power is absorbed by the isolation resistor 45. The magnitude of the resistance value of the isolation resistor 45 can be flexibly selected according to the simulation experiment result of the isolation degree of the power divider, and is not particularly limited herein. The isolation resistor 45 in this embodiment has a square shape with a side length of 1.524mm.

Fig. 5 is a simulation diagram of the insertion loss of the high-power high-selectivity multi-coupling microwave component and the isolation degree of the power divider, which are provided by the embodiment of the invention, and it is obvious that the return loss obtained by simulation of the high-power high-selectivity multi-coupling microwave component is below-18 dB, the insertion loss S21 and the insertion loss S31 of two output ends of the power divider are respectively 4.1dB and 5.5dB, and the main reasons for causing the insertion loss change are that the indexes of couplers formed on different branches are different. Meanwhile, the isolation S23 of two output ports of the power divider is below-26 dB, and the design standard is achieved.

Fig. 6 is a simulation diagram of the coupling degree of the high-power high-selectivity multi-coupling microwave assembly provided by the embodiment of the invention, and it is obvious that the coupling coefficients S81, S61 and S41 of different couplers obtained by simulation of the high-power high-selectivity multi-coupling microwave assembly of the invention correspond to 8dB, 12dB and 16dB couplers respectively. In the design process, the coupling quantity of the coupler can be adjusted by adjusting the distance and the line width of the coupling line, and finally, the coupling quantity of different standards can be achieved. Meanwhile, in FIG. 7, the isolation degree S91 of each coupler is below-20.8 dB, S71 is below-21 dB, S51 is below-27 dB, the design requirement is met, and FIG. 8 is a simulation diagram of the isolation degree between the coupling ends of different couplers. According to the calculation of the direction of fig. 9, it is guaranteed in its entirety between-11 dB and-13 dB.

When the simulation is performed by icepak software under the high-power scene, as shown in fig. 10, the temperature is 87.5 ℃ when the high-power high-selectivity multi-coupling microwave assembly works at 50W, and the standard used under the high-power condition is met.

The high-power high-selectivity multi-coupling microwave component has the characteristics of high integration level, small volume, wide bandwidth, high isolation, simple process and low cost, is matched with the trend of high integration and miniaturization of future circuits, and has the function of frequency selection, effectively eliminates multipath interference and noise, and ensures the purity and stability of signals. Meanwhile, the power divider has the function of dividing one path of signal energy into two paths or outputting equal or unequal energy by multiple paths, so that the transmission of multiple paths of signals is realized, and the efficiency of signal transmission is improved. The coupler is a radio frequency device for dividing one microwave power into a plurality of paths in proportion in a microwave system, and can realize the functions of power distribution, signal detection, isolation guarantee and signal processing, thereby realizing better effects of signal filtering, signal energy and power distribution.

The invention can be applied to the base stations of two major operators of 5G communication and telecommunication, and can be applied to the fields of high-frequency signal processing such as wireless communication, radar, satellite communication and the like, so that electric energy is effectively converted into useful signal energy, the energy loss is reduced, and the energy utilization efficiency of the base station is improved. Meanwhile, the method has more reliable performance, can lower the failure rate of base station equipment, improve the transmission capacity and coverage area of the base station, and effectively improve the economic benefit of the base station.

The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. The utility model provides a high-power high selectivity multi-coupling microwave subassembly which characterized in that: including wave filter (10), earth plane (20), dielectric substrate (30), merit divide ware and coupler, wave filter (10) set up the upper surface at earth plane (20), earth plane (20) set up the upper surface at dielectric substrate (30), merit divide the ware to set up the lower surface at dielectric substrate (30), wave filter (10) and dielectric substrate (30) material are the aluminium oxide, wave filter (10) include a plurality of resonant cavities, a plurality of resonant cavities size the same and inside are provided with the blind hole, blind hole radius the same but the degree of depth is different, a plurality of resonant cavities are connected gradually through the coupling window along u type or n type route direction, and the resonant cavity that is located the one end of u type or n type route has inserted first feed probe (11), and the resonant cavity of the other end has inserted second feed probe (12), and first feed probe (11) are connected with input microstrip line (60), and second feed probe (12) are connected with merit divide ware input (41), and merit divide output (42) to divide output (42) and regard as main coupler microstrip line coupling line and microstrip line (51) respectively.

2. The high power, high selectivity, multi-coupling microwave assembly of claim 1, wherein: the power divider comprises a first impedance converter (43), a second impedance converter (44) and an isolation resistor (45), wherein an input end (41) of the power divider is connected to an output end (42) of the power divider through the first impedance converter (43) and the second impedance converter (44) respectively, and the isolation resistor (45) is arranged at the inner side end, close to each other, of the first impedance converter (43) and the second impedance converter (44).

3. The high power, high selectivity, multi-coupling microwave assembly of claim 2, wherein: the power divider input end (41) is connected to a first power divider output end (421) through a first impedance converter (43), the power divider input end (41) is connected to a second power divider output end (422) through a second impedance converter (44), the branch coupling microstrip line (51) comprises a first branch coupling microstrip line (511), a second branch coupling microstrip line (512) and a third branch coupling microstrip line (513), the first coupler is formed by the power divider input end (41) and the first branch coupling microstrip line (511), the second coupler is formed by the power divider output end (421) and the second branch coupling microstrip line (512), and the third coupler is formed by the power divider output end (422) and the third branch coupling microstrip line (513).

4. A high power, high selectivity, multi-coupling microwave assembly as claimed in claim 3, wherein: the coupling degree of the first coupler is 8dB, the coupling degree of the second coupler is 16dB, and the coupling degree of the third coupler is 12dB.

5. The high power, high selectivity, multi-coupling microwave assembly of claim 1, wherein: the blind hole is located the center of resonant cavity, and a plurality of resonant cavities include first resonant cavity (13), second resonant cavity (14), third resonant cavity (15), fourth resonant cavity (16), fifth resonant cavity (17) and sixth resonant cavity (18), are provided with first blind hole (131) in first resonant cavity (13), are provided with second blind hole (141) in second resonant cavity (14), are provided with third blind hole (151) in third resonant cavity (15), are provided with fourth blind hole (161) in fourth resonant cavity (16), are provided with fifth blind hole (171) in fifth resonant cavity (17), are provided with sixth blind hole (181) in sixth resonant cavity (18).

6. The high power, high selectivity, multi-coupling microwave assembly of claim 5, wherein: a first square groove or a first round hole is formed between the first resonant cavity (13) and the sixth resonant cavity (18) to form inductive cross coupling, a second square groove or a second round hole is formed between the second resonant cavity (14) and the fifth resonant cavity (17) to form capacitive cross coupling, and a transmission zero point is introduced.

7. The high power, high selectivity, multi-coupling microwave assembly of claim 1, wherein: the first feed probe (11) and the second feed probe (12) are metal probes, the first feed probe (11) extends and penetrates through the ground layer (20) and the dielectric substrate (30) to be connected to the input microstrip line (60), and the second feed probe (12) extends and penetrates through the ground layer (20) and the dielectric substrate (30) to be connected to the input end (41) of the power divider.

8. The high power, high selectivity, multi-coupling microwave assembly of claim 7, wherein: and the input microstrip line (60) and the second feed probe (12) are both added with a metal shielding cover (70), and the metal shielding cover (70) is connected with the grounding layer (20) for blocking electromagnetic waves.

9. The high power, high selectivity, multi-coupling microwave assembly of claim 1, wherein: the characteristic impedance of the input microstrip line (60) is 50 ohms.

10. The high power, high selectivity, multi-coupling microwave assembly of claim 1, wherein: the dielectric substrate (30) has a relative permittivity of 9.8, a loss tangent of 0.00014, and a thickness of 1.524mm.