CN109149036B

CN109149036B - Filter structure

Info

Publication number: CN109149036B
Application number: CN201810879223.8A
Authority: CN
Inventors: 苏华峰; 张利鹏; 陈开宏; 王照; 何丽娥; 陈馥汇
Original assignee: N Radio Technologies Co ltd
Current assignee: N Radio Technologies Co ltd
Priority date: 2018-08-03
Filing date: 2018-08-03
Publication date: 2024-05-07
Anticipated expiration: 2038-08-03
Also published as: CN109149036A

Abstract

The invention relates to a filter structure, comprising a grounding plate as the lower ground and a cover plate as the upper ground; a pin arranging wall formed by periodically arranging pins is arranged between the grounding plate and the cover plate; the bottom of the pin-array wall is arranged on the grounding plate and is electrically connected with the grounding plate, and a gap is formed between the top of the pin-array wall and the cover plate to form an artificial band gap structure. The invention adopts the clearance cavity filter technology of pin array technology, avoids contact between metals, and has simple processing technology and assembly and low material cost.

Description

Filter structure

Technical Field

The invention relates to the field of electronic components, in particular to a filter structure.

Background

In the filter reality technology, two technologies for realizing a high Q value (quality factor) are mainly adopted, one is a metal cavity coaxial cavity structure, and the other is a metal waveguide filter structure. The coaxial cavity structure filter of metal cavity mainly includes: (1) The metal coaxial resonant rod plays a role in adjusting resonant frequency; (2) metal coaxial resonant cavity ground; (3) The metal cover plate is sealed on the cavity and fastened by a screw; (4) walls of the metal cavity; (5) And the debugging screw is arranged on the metal cover plate and used for realizing the adjustment of the resonant frequency and the energy coupling between the resonant cavities. The above 5 parts are combined together to form a closed resonant cavity structure, and a complete filter is finally formed through coupling between the resonant cavities. The waveguide filter scheme is a variant of the coaxial filter, and the waveguide filter can be obtained by removing the coaxial resonant rod in the coaxial filter. Coaxial filters are commonly used in the radio frequency domain, while waveguide filters are used in the microwave and millimeter wave domain.

With the development of technology, there is also a structure related to a gap waveguide in recent years, and the structure is respectively formed by surrounding a metal ground, a metal cover plate and a periodic metal column together; an artificial magnetic conductor surface (AMC) or an electromagnetic band gap structure (EBG) formed by the contact of the periodic metal columns and the metal ground, and in addition, a gap smaller than a quarter wavelength is reserved between the periodic metal columns and the metal cover plate, so that a complete gap waveguide single resonant cavity structure is formed.

The first two filters of the prior art are fastened by using screws and close the whole resonant cavity, and in the microwave and millimeter wave fields with higher frequency, the cover plate needs to be further welded and closed. The whole resonant cavity is fastened and sealed by a large number of screws, the engineering is very complicated, the assembly is time-consuming and labor-consuming, the materials are various due to excessive welding and fastening screws, the cost is increased, a large number of metal contacts occur in the fastening process, the metal nonlinear effect is easy to cause, the passive intermodulation problem occurs to microwave or radio frequency signals, and the passive intermodulation is the technical problem which is most difficult to solve in the current communication technical field. The existing gap waveguide structure has the difficult problem of difficult machining, and the periodic metal column of the gap waveguide has the technical problems of long machining period, easy damage to machining tools and raw materials, high cost and the like under the current machining technology.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: a filter is provided that avoids metal-to-metal contact, reducing significant assembly time, material costs, and complex machining processes.

In order to solve the technical problems, the invention adopts the following technical scheme:

a filter structure comprising a ground plate as an underlying ground and a cover plate as an overlying ground; a pin arranging wall formed by periodically arranging pins is arranged between the grounding plate and the cover plate; the bottom of the pin-array wall is arranged on the grounding plate and is electrically connected with the grounding plate, and a gap is formed between the top of the pin-array wall and the cover plate to form an artificial band gap structure.

The top of the pin-arranging wall forms an artificial magnetic conductor surface, the side surface of the pin-arranging wall forms an artificial electromagnetic soft surface, and an interception mode is formed for the electromagnetic wave in transmission, so that the electromagnetic wave cannot penetrate through the artificial electromagnetic soft surface; the interval between the top of the pin-arranging wall and the cover plate is not more than one quarter of the working wavelength, and the gap between the side surfaces of the pins forms the artificial electromagnetic soft surface; the cover plate is a metal cover plate and/or a PCB (printed circuit board); the pin header is a metal thin rod; the grounding plate is connected with the pin header through a reflow soldering process; the grounding plate is a PCB grounding plate, copper plated or silver plated metal sheet; the top of the row needle is provided with a mushroom-like head patch to reduce the size.

The grounding plate, the pin header wall and the cover plate jointly enclose a plurality of resonant cavities of the filter, and the filter structure is separated to form a plurality of filters; each filter is provided with a pair of grounding feed probes, the grounding feed probes carry out coupling feed on the filter, and the energy of the filter is conducted to the outside of the filter in a capacitive coupling mode; a resonant column is arranged in the resonant cavity; a coupling enhancement block is arranged in the filter; two adjacent filters in the plurality of filters are respectively provided with a probe to form a pair of symmetrical probes, and the symmetrical probes form symmetrical zero points in the filters; the filter structure also comprises a needle arrangement seat, and the periodic needle arrangement of the needle arrangement wall is connected into a whole by the needle arrangement seat.

An input/output PCB is arranged at the top of the filter; the bottom of the grounding feed probe is electrically connected with the grounding plate and grounded, and the top of the grounding feed probe is electrically connected with the input/output PCB; the input/output PCB is assembled on the outer side of the top of the cover plate, and the top end of the ground feed probe penetrates through the cover plate and a via hole arranged on the input/output PCB; the input/output PCB is provided with an input/output connector which is electrically connected with the outside, and the input/output connector is electrically connected with the top end of the grounding feed probe through a microstrip line; the pair of ground feed probes are respectively positioned in the first resonant cavity and the last resonant cavity, and the signals of the first resonant cavity and the last resonant cavity are transmitted to the input/output PCB in a capacitive coupling mode to be connected with the outside; the resonant cavities are mutually coupled; the coupling enhancement block is arranged on the grounding plate and is electrically connected with the grounding plate; the resonance column is arranged on the grounding plate and is electrically connected with the grounding plate; the coupling enhancement block is arranged between the adjacent resonant cavities; two probes of the symmetrical probes are respectively arranged between the first resonant cavity and the last resonant cavity of each of the two adjacent filters to realize symmetrical zero points; each resonant cavity is provided with a resonant column at the center.

The coupling enhancement block comprises a horizontal flaky body, and pins are vertically arranged downwards at two sides of the horizontal flaky body; the symmetrical probes are of a T-shaped PCB structure, wherein the part with the electric effect is positioned at the top of the T-shaped structure, the part without the electric effect is positioned at the bottom, the bottom extends downwards to form pins, and no electric connection exists between the pins at the top and the bottom of the PCB structure; the symmetrical probes are vertical slices; the grounding feed probe comprises a vertical body, wherein the vertical body is in a vertical sheet shape, the vertical body extends upwards to form an upper pin, the upper pin penetrates through the cover plate to be connected with the input/output PCB, and the vertical body extends downwards to form a grounding pin; the pins of the coupling enhancement block, the pins of the symmetrical probes and the grounding pins of the grounding feed probes are welded on the grounding plate.

The coupling enhancement block comprises a horizontal sheet-shaped body, a pair of opposite pins and a third pin, wherein the horizontal sheet-shaped body of the coupling enhancement block extends downwards and vertically to form three pins, the three pins extend downwards from two ends of the same side of the horizontal sheet-shaped body to form a pair of opposite pins, the middle part of the opposite side extends downwards and vertically to form the third pin, and the pins are arranged in a step shape; the pins of the symmetrical probes extending downwards are stepped; the upright body of the feed probe extends upwards to form a step-shaped upper pin, and the upper pin penetrates through the cover plate, is inserted into a through hole arranged on the input/output PCB and is welded to the input/output PCB; the bottom of the feed probe body is provided with three grounding pins, the middle of the feed probe body downwards extends to form a narrower middle pin, two sides of the feed probe body laterally and vertically form a pair of left and right pins, and the grounding pins are in a step shape; a plurality of coupling enhancement blocks are arranged in the same filter, and one sides of the coupling enhancement blocks, provided with a pair of pins, are opposite; the grounding plate is provided with through holes, and pins of the coupling enhancement block, pins of the symmetrical probes and grounding pins of the grounding feed probes are inserted into the corresponding through holes and welded on the grounding plate.

The filter structure further comprises an outer cavity serving as a middle ground, and the grounding plate and the cover plate are respectively fastened at the bottom and the top of the outer cavity; the inner wall of the outer cavity is vertically provided with a plurality of screw grooves, fastening screws penetrate through the grounding plate and penetrate upwards into the lower sections of the screw grooves to be fastened, the fastening screws penetrate through the cover plate and penetrate downwards into the upper sections of the screw grooves to be fastened, and the inner wall of the outer cavity is further provided with vertical ribs; a plurality of debugging screws for adjusting the coupling between the resonant frequency of the filter and the resonant cavity are arranged on the cover plate, and penetrate through the cover plate and downwards extend into the resonant cavity; the bottom end of the debugging screw is positioned above the coupling enhancement block, the symmetrical probe and the resonant column; the needle arrangement seat is arranged in the outer cavity and is abutted and fixed by vertical ribs on the inner wall of the outer cavity.

The pin array wall, the grounding feed probe, the coupling reinforcing block, the symmetrical probe and the resonant column are welded into the grounding plate to form a core part of the filter structure; the input and output connectors are welded into the input and output PCBs to form an input and output PCB whole, and the input and output PCB whole and the debugging screw are assembled on the cover plate to form a cover plate whole; the core part and the cover plate of the filter are respectively fastened together in contact with the outer cavity by fastening screws, and the input/output PCB and the feed probe in the core part of the filter are welded together to form a filter structure; the debugging screw is fastened to the cover plate by means of a metal gasket and a fastening nut.

The needle arrangement seat is a connecting structure made of non-conductive medium material; the pin row wall is pressed into the pin row seat so as to connect the periodic pin row into an integral structure; the needle arrangement seat is provided with perforations, and each needle arrangement seat passes through one perforation to be fixedly connected; the grounding plate is provided with a metallized via hole, the metallized via hole is arranged corresponding to the periodic pin header and/or the perforation on the pin header, and the bottom end of each pin header is inserted into one metallized via hole after passing through the perforation on the pin header and welded on the grounding plate; in each filter, the pin-arranging wall comprises a pin-arranging annular array positioned at the periphery and a pin-arranging separation array positioned at the center of the filter, and the pin-arranging separation array separates one filter into a plurality of resonant cavities; two adjacent filters are parallel and adjacent with one side of the pin array.

The separation array comprises a pin row crisscross array formed by a plurality of transverse rows and vertical rows of pin rows in a crossed arrangement; the periodic row pins are aligned with the vertical rows from one side of the annular array to form an extended vertical row array, the extended vertical row array is separated from the vertical row pins of the crisscross array by a gap, and one of the pair of symmetrical probes is transversely arranged in the gap; the crisscross pin array divides each filter into four resonant cavities, and the resonant cavities in two adjacent filters are symmetrically arranged.

The needle arrangement seat in the two adjacent filters comprises a non-conductive medium frame body with an integral structure, a plurality of circles of perforations are arranged on the frame body, and the needle arrangement annular array is correspondingly pressed into the circles of perforations; the needle arrangement seat also comprises a medium separation section, the medium separation section is connected with the relative bottom edge of the medium frame body, the medium separation section is provided with a plurality of vertical row perforations, and the row pairs positioned on the side edges of the two annular arrays which are adjacent in parallel are correspondingly pressed into the plurality of vertical row perforations to form an integral structure; the medium separation section divides the needle arrangement seat into two needle arrangement seat units, corresponding to each filter, the center of each needle arrangement seat unit is provided with a crisscross medium body, the crisscross medium body is provided with a plurality of transverse rows and vertical rows of perforations which are arranged into a crisscross perforation arrangement, and the crisscross needle arrangement seat array is pressed into the perforations on the crisscross medium body to be connected into an integral structure; a bottom edge of the dielectric frame body extends to form a section of vertical dielectric body, and is aligned with the vertical bottom end of the cross-shaped crossed dielectric body at intervals of the gap; a plurality of vertical row perforations are arranged on the vertical dielectric body, and a vertical row array extending from the row pins is pressed into the plurality of vertical row perforations to be connected into an integral structure; the annular array of the pin header wall is a square array.

Three coupling enhancement blocks are arranged in one filter, and one of the three coupling enhancement blocks and the symmetrical probes is respectively positioned at the outer side of the cross-shaped tail end of the cross pin array and is spaced from the cross-shaped tail end by a certain gap.

The beneficial effects of the invention are as follows:

According to the filter structure, a gap is reserved between the cover plate and the cavity by adopting the gap cavity filter technology of the pin arranging technology, so that contact between metals is avoided, the processing technology and the assembly are simple, and the material cost is low.

The coaxial or waveguide resonant cavity structure formed by the joint enclosure of the pin array technology, the grounding plate (including the PCB grounding plate) and the metal cover plate (including the metal cover plate realized in other forms, such as the PCB) has better filtering performance.

The present invention will be described in further detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a perspective view of a filter structure according to an embodiment of the present invention.

Fig. 2 is a top view of an embodiment of the filter structure of the present invention with the upper cover assembly removed.

Fig. 3 is a top view of a filter structure according to an embodiment of the invention.

Fig. 4 is a cross-sectional view of the filter structure of fig. 3 along line B-B.

Fig. 5 is a cross-sectional view of the filter structure of fig. 3 taken along line B-B, wherein fig. (a) is an orthographic view and fig. (B) is a partial enlarged view corresponding to region a in fig. (a).

Fig. 6 is a six-sided view of a filter structure of an embodiment of the present invention.

Fig. 7 is an exploded view of a filter structure of an embodiment of the present invention.

Fig. 8 is an enlarged view of a part of the structure of the filter structure of the embodiment of the present invention.

Fig. 9 is a structure and layout diagram of a debug screw of a filter structure according to an embodiment of the present invention.

Fig. 10 is an enlarged view of a part of the structure of the filter structure of the embodiment of the present invention.

Fig. 11 is a periodic array single-cell brillouin graph and single-cavity energy distribution diagram of a filter according to an embodiment of the present invention.

Fig. 12 is a graph of filter WIFI 36 channel filter results for an embodiment of the invention.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other, and the present application will be further described in detail with reference to the drawings and the specific embodiments.

Referring to fig. 1 to 10, the present invention provides a filter structure 100, which includes a ground plate 2, an outer cavity 3 and a cover plate 9 fastened together, and a closed cavity is formed therein. The cavity is internally provided with a needle arrangement seat 4 and a needle arrangement wall 5 formed by surrounding periodic needle arrangement.

A pin arranging wall 5 formed by arranging periodic pin arranging 50 is arranged between the grounding plate 2 and the cover plate 9; the bottom of the pin-array wall 5 is mounted on the grounding plate 2 and is electrically connected, and a gap is formed between the top of the pin-array wall and the cover plate 9, so that an artificial band gap structure is formed. The top of the pin-arranging wall forms an artificial magnetic conductor surface, the side surface of the pin-arranging wall forms an artificial electromagnetic soft surface, and an interception mode is formed for the electromagnetic wave in transmission, so that the electromagnetic wave cannot penetrate through the electromagnetic wave. The interval between the top of the pin header 5 and the cover plate 9 is not more than one quarter of the working wavelength.

The cover plate 9 is a metal cover plate and/or a PCB (printed circuit board); the pin header 5 is a metal thin rod; the ground plate 2 and the pin header 50 are connected by a reflow process.

The grounding plate is a PCB grounding plate, copper plating or silver plating metal sheet. In the following embodiments, the ground plate 2 is taken as a PCB ground plate as an example, and the ground plate 2 is the ground of the pin header and the main components of the filter, which is the lowest ground of the filter structure. The outer cavity 3 is an outer cavity, and serves as the middle ground of the filter structure, and supports the PCB ground plate 2 and the cover plate 9 of the filter to form an outer wall of the peripheral side wall. The cover plate 9 is a metal cover plate, which serves as the uppermost ground in the filter structure. The periodic pin arranging wall 5 is pressed into the pin arranging seat 4 to form a pin arranging structure. The cavity is also provided with a ground feed probe 61, a coupling enhancement block 62, a PCB symmetry probe 7 and a resonant column 8 which are mounted on and electrically connected to the PCB ground plate 2.

Referring to fig. 2, the filter structure 100 of the present embodiment includes two adjacent filters 101, i.e., a first filter and a second filter, respectively, separated by a Y-axis, and four single cavities, i.e., resonant cavities 18, are formed in each filter 101 by a center-located cross pin array. It will be appreciated that the filter structure 100 may also comprise a single filter or a plurality of filters. The ground plate 2, the pin header structure and the cover plate 9 enclose a resonant cavity 18. The adjacent resonators 18 of the two filters are coupled to each other and the coupling is further enhanced by a coupling enhancement block 62.

The periodic pin-array wall 5, the ground feed probes 61, the coupling enhancement blocks 62, the PCB symmetry probes 7 and the resonant posts 8 are soldered to the PCB ground plate 2, thereby forming the core of the inventive filter structure 100. Instead of soldering, the periodic pin-array wall 5, the ground feed probes 61, the coupling reinforcing blocks 62, the PCB symmetry probes 7 and the resonant posts 8 may be mounted on the PCB ground plate 2 and electrically connected to the PCB ground plate 2 by plugging or clamping or other mounting means.

Referring again to fig. 2 and 6, the PCB ground plate 2 serves as a ground plate, and is electrically connected to the periodic pin array wall 5, the ground feed probes 61, the coupling reinforcing blocks 62, the PCB symmetrical probes 7, and the resonant posts 8, and vias, solder joints, pads, or interfaces are provided on the PCB ground plate 2 to interface with the above elements. The periodic pin-array wall 5, the ground feed probes 61, the coupling reinforcing blocks 62, the PCB symmetrical probes 7, and the resonant posts 8 may be soldered to the PCB ground plate 2 by a reflow soldering process. The PCB grounding plate 2 is provided with pin holes which are consistent with the pin-arranging wall 5 in shape, the arrangement of the pin holes of the PCB grounding plate 2 is consistent with the periodic arrangement of the pins of the pin-arranging wall 5, and the bottoms of the pins are inserted into the pin holes. The pin holes of the PCB grounding plate 2 are metal through holes. The bottom of the pin header 5 is inserted into a metal via hole on the PCB ground plate 2, and is soldered and fixed by a reflow soldering process. Pins of the pin header beyond the PCB ground plate portion are reflow soldered to the PCB ground plate 2.

Referring to fig. 6-8, a rectangular PCB ground plate 2 is provided with a plurality of (e.g. 3) rows of pinholes (metallized vias) near the edge thereof, two sides of the middle Y-axis are symmetrically arranged by a plurality of vertical rows (e.g. four vertical rows for each of left and right Y-axis), and two symmetrical ground plate units are enclosed by the Y-axis, each ground plate unit corresponds to a filter 101, and a plurality of circles of pinholes are provided around the ground plate unit and a plurality of vertical rows (e.g. two rows of four vertical rows) of pinholes are provided in the middle of the ground plate unit. The center of the grounding plate unit is configured into cross-shaped row pinholes by intersecting a plurality of transverse rows and vertical row pinholes (for example, three transverse rows and three vertical rows are intersected), one side of each circle of surrounding row pinholes extends inwards to be aligned with the vertical row in the cross-shaped row pinholes by a section of vertical row pinholes with corresponding row number, a certain gap 21 (figure 8) is formed between the surrounding circle of row pinholes and the bottom of the vertical row pinholes of the cross-shaped row pinholes, and the gap 21 between two sections of vertical row pinholes (the crossed vertical rows and the vertical rows with one side extending inwards) on the PCB grounding plate 2 is used for installing the symmetrical probes 7. It will be appreciated that the vertical and horizontal rows are relative, in this embodiment the vertical row direction corresponds to the Y axis. The gap 21 between two sections of vertical rows of pinholes in two adjacent floor units is symmetrical about the Y-axis. On the PCB grounding plate 2, a coupling reinforcing block 62 is arranged above the tops of the vertical rows in the cross-shaped pin holes at intervals, and the coupling reinforcing blocks are respectively arranged at two opposite ends of the cross-shaped vertical rows with the probes 7 arranged in the gap 21. The pair of coupling reinforcing blocks 62 are symmetrically installed at the left end and the right end of the cross-shaped transverse row pin holes at certain intervals. Four areas separated by cross pin holes correspond to four single cavities (resonant cavities) 18, and a resonant column 8 for reducing the resonant frequency is arranged in the center of the grounding plate corresponding to each single cavity 18. In a filter there are four resonators 18 and the resonator columns 8 are symmetrical to each other. Three coupling enhancement blocks 62 and one symmetrical probe 7 are located between adjacent resonators, respectively. A symmetry zero is realized in a symmetry probe 7 between the first and the last resonator of the two filters, respectively.

The corners of the PCB ground plate 2 are provided with a chamfer structure.

The periphery of the PCB ground plate 2 is provided with screw holes (not shown), and a plurality of screw holes are uniformly distributed on the periphery.

The outer cavity 3 forms an annular closed side wall or outer wall of the filter structure and is used for supporting the cover plate 9, and can be made of metal or nonmetal materials; the square frame structure is illustrated as an example in the drawings. The inner wall of the frame-like structure is vertically provided with a number of screw grooves 31. The inner wall may also be formed with several vertical ribs 32 for abutment against the needle arrangement holder 4 and for better electrical performance. In the example shown in the figure, two vertical ribs 32 are symmetrically arranged on the left and right inner side walls of the outer cavity 3. The height of the outer cavity 3 is higher than the height between the top of the pin header wall 5 and the PCB grounding plate 2, and is not more than one quarter of the operating wavelength. In one specific example, the height is 0.5mm.

The PCB ground plate 2 is fastened to the lower end of the outer cavity 3 by the ground plate fastening screw 1. The fastening screw 1 passes through the PCB grounding plate 2 upwards from the periphery of the PCB grounding plate 2 and is inserted into the outer cavity 3, and is inserted into a screw groove 31 arranged on the inner side wall of the outer cavity 3 to be in clamping fit, and can be fixed in a threaded fit mode. The ground plate fastening screw 1 extends from the bottom of the screw groove 31 into the lower section of the screw groove 31.

The pin-arranging wall 5 is surrounded by periodic pins 50, and each pin 50 can be formed by slender copper thin rods or other metal thin rods. In each filter 101, the pin-arranging wall 5 comprises a pin-arranging annular array 51 positioned at the periphery and a pin-arranging separation array 52 positioned at the center of the filter, and the pin-arranging separation array 52 separates one filter 101 into a plurality of resonant cavities 18; two adjacent filters are juxtaposed adjacent one another in a side 53 of the pin array.

In a specific embodiment, the separation array 52 includes a pin cross array formed by a plurality of horizontal pins 520 and vertical pins 521 arranged in a cross manner; from one side of the annular array 51, aligned with the vertical row pins 521, the periodic pins are further arranged to form an extended vertical row array 54, the extended vertical row array 54 being spaced from the vertical row pins 521 of the crisscross array by a gap 21, one of the pair of symmetrical probes being mounted transversely to the gap 21; the crisscrossed pin array divides each filter into four resonant cavities 18, with the resonant cavities in adjacent two filters 101 being symmetrically arranged.

In the embodiment shown in fig. 6-8, the pins 50 in two adjacent filters 101 are periodically arranged in a plurality of circles, for example, three circles of pins are arranged in a rectangular array (including two annular arrays 51), and each circle is formed by 138 pins in a rectangular array twice as wide (i.e., each annular array 51 is square), so as to be divided into two square pin wall units in the middle vertical direction (Y-axis direction). The middle is arranged with a plurality of columns along the Y-axis direction (for example, four columns are formed by Y-axis center lines), and the center is divided into two adjacent pin-array wall units (corresponding to one pin-array annular array 51) corresponding to the two filters. In each pin field unit, a group of vertical arrays 54 (for example, three vertical rows of four pins) are sequentially arranged from one side edge of the pin field annular array 51 inwards along the parallel direction (or vertical direction) of the Y axis. The end of the vertical row array 54 is further periodically arranged by pins 50 to form the crisscross array, for example, 9 pins for each of three vertical rows and 9 pins for each of three horizontal rows form the crisscross array.

The cross section of the single pin header 50 can be square or round, or mushroom-like head patches can be placed on the cross section, so that equivalent capacitive coupling among the pin headers is increased, the pin header height is reduced, and the pin header and pin header wall size are reduced.

The number of the pins in each pin array can be adjusted, and the number of the pins can be adjusted as required. The required electrical performance of the filter is obtained after adjustment. The height of the pin header is smaller than the height of the outer cavity 3.

The arrangement mode and the number of the pin headers are specifically configured according to the actual size of the filter. The pin header length is set in conjunction with the operating frequency of the filter, and the specific size may be determined by the operating frequency. For example, the operating frequency is 5GHz and the length is selected to be 16.5mm. The corresponding pin header and pin header wall can be configured by one skilled in the art according to the specific filter selected. In the concrete implementation, the pin header and the pin header wall can be selected and configured according to the existing specification of the manufacturer.

The number and arrangement of the pin array 50 of the pin array wall 5, the number and arrangement of the through holes 40 arranged on the pin array seat 4, and the number and arrangement of pin array holes (metallized through holes) 50 arranged on the PCB grounding plate 2 are in one-to-one correspondence. The pin header of the pin header wall 5 is inserted into the through holes 40 of the pin header seat 4 to be connected to form an integral pin header structure, and the bottom of the pin header wall 5 is welded to the PCB grounding plate 2.

The pin header 4 is a non-conductive medium base body, and is made of plastic or other non-conductive medium materials, and corresponds to the shape of the pin header wall 5, so as to fixedly connect the periodic pins of the pin header wall 5 into a whole. The needle arrangement seat is provided with perforations 40, and each needle arrangement 50 is fixedly connected through one perforation 40; the ground plate 2 is provided with metallized through holes 20, the metallized through holes 20 are arranged corresponding to the periodic pin arrangement and/or the perforations 40 on the pin arrangement seat, and each pin arrangement 50 is inserted into one metallized through hole 20 at the bottom end after passing through the perforations 40 on the pin arrangement seat 4 and welded on the ground plate 2.

The needle arrangement seat 4 in the two adjacent filters 101 comprises a non-conductive medium frame 41 with an integral structure, a plurality of circles of perforations 40 are arranged on the frame 41, and the needle arrangement annular array 51 is correspondingly pressed into the circles of perforations; the needle arrangement seat 4 further comprises a medium separation section 43, the medium separation section 43 is connected with the opposite bottom edges of the medium frame 41, the medium separation section 43 is provided with a plurality of vertical row perforations, and the row pair positioned at the side 53 of the two annular arrays 51 which are adjacent in parallel is correspondingly pressed into the plurality of vertical row perforations to form an integral structure; the medium separation section 43 divides the needle arrangement seat 4 into two needle arrangement seat units, corresponding to each filter 101, the center of each needle arrangement seat unit is provided with a crisscross medium body 42, the crisscross medium body is provided with a plurality of transverse rows and vertical rows of perforations which are arranged into a crisscross perforation arrangement, and the crisscross needle arrangement seat array is pressed into the perforations on the crisscross medium body to be connected into an integral structure; a bottom edge of the dielectric frame 41 extends to form a vertical dielectric body 44 aligned with the vertical bottom end of the cross-shaped crossed dielectric body 42 with the gap 21 therebetween; the vertical dielectric body 44 is provided with a plurality of vertical row perforations, and the vertical row array 54 extending from the row pins is pressed into the plurality of vertical row perforations to be connected into an integral structure; the annular array 51 of the pin header 5 is a square array.

The pin header 4 is made of non-conductive medium material, the through holes arranged on the pin header 4 are in one-to-one correspondence with the pins of the pin header wall 5, each pin header penetrates into one perforation 40 of the pin header 4 to be fixed, and the periodically arranged pins in the pin header wall 5 are respectively inserted into the perforation 40 of the pin header 4 to be fixed so as to form a pin header structure.

The pin header 4 may be formed of various dielectric materials, and may even be air. In this embodiment, the pin header 4 is used to fix all pins 50 together and form a whole, and the pin header 4 only has the functions of supporting and fixing, has no other electrical performance requirements, and has no holes for metallization.

Referring again to fig. 2-10, a feed and coupling structure 6 is also provided in the filter structure of the present invention, the feed and coupling structure 6 comprising an input-output grounded feed probe 61 and a coupling enhancement block 62. The ground feed probe 61 conducts the filter energy to the outside of the filter by means of capacitive coupling and the coupling enhancement block 62 serves to increase the coupling between the resonant cavities 18. In this embodiment, the ground feed probe 61 adopts a capacitive coupling feed mode of a ground mode, and the size of the area of the feed structure and the distance from the resonant rod (i.e., the resonant column 8) determine the intensity of the coupled energy, so that the larger the area, the stronger the coupled energy; the closer the distance the stronger the energy coupled out.

The ground feed probe 61 includes a vertical body 610, the body 610 is in a vertical sheet shape, the upward extending width is narrowed to form a step shape, the top is narrower to form an upper pin 613 extending upward to facilitate the electric connection by soldering on the input/output PCB 11 after passing through the cover plate 9, and the bottom of the vertical body 610 is provided with a ground pin including a middle pin 611 and left and right pins 612. The middle of the bottom of the body 610 extends downwards to form a narrower middle pin 611, and is soldered to the PCB ground plate 2 to be electrically connected, thereby forming a capacitive coupling feeding mode of a grounding mode. A pair of left and right pins 612 are formed vertically and laterally on both sides of the body 610, and are welded on the PCB ground plate 2 in a downward extending manner, and grooves are formed at the connection positions of both sides of the body 610 and the left and right pins 612. The inner sides of the left and right pins 612 near the body are formed in a step shape to facilitate welding fixation. The three pins at the bottom of the ground feed probe 61 are respectively located at two sides and in the middle and welded to the PCB ground plate 2, and the upper pins formed by extending the top upwards are welded to the input/output PCB 11. A pair of ground feed probes 61 is disposed in each filter 101, and a pair of ground feed probes 61 are symmetrically disposed within two adjacent resonators 18. The ground feed probes 61 in two adjacent filters are symmetrically arranged. Preferably, one ground feed probe 61 is disposed in each of the first and last resonators of the same filter.

The corresponding metallized via holes 20 are arranged on the PCB grounding plate 2, the lower pins of the grounding feed probes 61 are correspondingly inserted into the metallized via holes 20 to penetrate out of the PCB grounding plate 2, and the excess parts are welded through reflow soldering, referring to the rear view of fig. 6.

The body 620 of the coupling enhancement block 62 is in a horizontal sheet shape, and pins are vertically arranged at two sides of the horizontal sheet body 620 downwards and are welded with the PCB ground plate 2 to realize electrical connection. Wherein, two ends of the same side of the sheet-shaped body 620 extend downwards to form a pair of opposite pins 621, and steps are formed on the pair of pins, preferably, the steps on the pair of pins are oppositely arranged, which is beneficial to welding and plugging fixation. The other side of the body 620 extends vertically downward from the middle to form a third leg 622. The three pins are welded with the PCB grounding plate 2 to realize electric connection. The pins 622 narrow down to form a mesa, e.g., T-shaped in cross-section, with the stepped pins facilitating solder attachment. The three pins of the coupling enhancing block 62 are distributed in a triangle shape, and are respectively located at the vertices of the triangle, for example, form an isosceles triangle, and a pair of pins disposed on the same side are located at the bottom side of the triangle. Each filter comprises a pair of coupling enhancement blocks 62 and a third coupling enhancement block 62 which are symmetrical left and right, and are respectively positioned at three ends of a cross shape of the pin header crisscross array, and the probe 7 is positioned at the other end of the cross shape. Accordingly, three coupling enhancement blocks 62 are oppositely disposed with the sides of the pair of pins 621 facing inwardly.

Three coupling enhancement blocks 62 and one probe 7 are arranged between every two adjacent resonant cavities 18 of the four resonant cavities 18, i.e. at the four ends of the pin-array crisscross array in the centre of the filter. A pair of ground feed probes 61 are located in adjacent cavities on either side of the probe 7 and are disposed between a bottom edge of the pin array ring array and the resonator posts 8 in the center of the cavities.

The corresponding metallized through holes 20 are arranged on the PCB grounding plate 2, and pins of the coupling enhancement block 62 are correspondingly inserted into the metallized through holes to penetrate out of the PCB grounding plate 2, and the excess part is welded through a reflow welding process. Refer to fig. 6. The larger the area of the coupling enhancement block 62, the higher the height, the stronger the mutual coupling between the resonators.

Two adjacent filters of the filter structure 100 are respectively provided with a probe 7 to form a symmetrical probe 7, so that a symmetrical probe structure of a PCB with symmetrical zero points is formed, the introduction of the symmetrical zero points can increase the out-of-band attenuation of the filters, and the symmetrical probe structure is a preferred mode for realizing the symmetrical zero points. The symmetrical probes 7 are of a T-type PCB structure in which the copper foil portion with electrical action is located at the top of the T-type structure and the copper foil portion without electrical action is located at the bottom, the bottom extending downward to form pins for soldering, there being no electrical connection between the top and bottom. The symmetrical probes 7 shown in fig. 10 are of a T-shaped vertical sheet structure, and the pins extending downwards are stepped to facilitate soldering and fixing to the PCB ground plate 2. As can be seen from fig. 4-6, the PCB ground plate 2 is provided with a metallized via hole 20, the pins of the symmetrical probes 7 are inserted into the metallized via hole to pass through the PCB ground plate 2, the ends of the pins extend out of the PCB ground plate 2, and the excess parts are soldered by a reflow soldering process. The two probes of the symmetrical probe 7 are respectively arranged between the first resonant cavity and the last resonant cavity of each of the two adjacent filters 101 to realize symmetrical zero points.

The resonant pillars 8 serve to lower the resonant frequency. The introduction of the resonant pillars 8 can greatly reduce the resonant frequency and reduce the filter volume. Each resonator unit comprises four resonant cavities 18, a resonant column 8 is arranged in the center of each resonant cavity 18, the bottom of each resonant column 8 is welded on the PCB grounding plate 2, and the top of each resonant column is positioned below the bottom end of the debugging screw 14.

The cover plate 9 is the uppermost ground in the filter structure, covers the top of the outer cavity 3 and is fixed by screws. Screw holes are formed in the periphery of the metal cover plate 9, and mounting holes for debugging screws are formed in the middle of the metal cover plate. Cover plate fastening screws 10 are inserted through screw holes around the cover plate 9 and extend downward into screw grooves 31 of the inner wall of the outer chamber 3, thereby fastening the cover plate 9 and the outer chamber 3. The screws 1 and 10 can be inserted into the bottom and top of the screw grooves 31 of the inner wall of the outer cavity 3, respectively, for fastening.

The input/output PCB 11 is used for connecting the ground feed probe 61 to the connector 12 through a microstrip on the input/output PCB to form the whole input/output PCB. The input/output PCB 11 is provided with screw holes, pin insertion holes of the input/output connector 12, and insertion holes of the feed probe 6. The fastening screw 13 is fastened from top to bottom through the input/output PCB 11 and the cover plate 9, thereby fastening the cover plate 9, the PCB 11 at the top end of the outer cavity 3. The top pins of the feed probes 6 extend up through the receptacles of the cover plate 9 and are soldered to the input-output PCB 11 for electrical connection. The input/output connectors 12 are provided with an output interface for electrical connection with the outside, and pins are provided at the bottoms thereof, as shown in fig. 1 and 4-7, and each input/output connector 12 is provided with 5 pins, four of which are ground pins and one of which is a feed pin. Pins of the input/output connector are inserted into pin holes of the input/output PCB 11 and welded on the bottom surface of the PCB 11 to realize electrical connection, and are electrically connected with the ground feed probe 61 through a microstrip on the input/output PCB, so that signals of the resonant cavities where the ground feed probe 61 is located are transmitted to the input/output PCB 11 through capacitive coupling (namely, the first resonant cavity and the last resonant cavity), and finally, the filter is connected with the outside through the connector 12. Each filter is provided with a pair of input and output connectors 12 which are positioned at the outer top end of the filter, and two adjacent filters are provided with two pairs of connectors 12 which are correspondingly and electrically connected with an input and output grounding feed probe 61 through a microstrip on an input and output PCB.

Two sets of 7 sets of tuning screws 14 are shown, for example, each set of 7 sets of tuning screws 14 are arranged in a circle, pass through screw holes arranged on the upper cover 9 from top to bottom, extend into the resonant cavity from bottom to bottom, are positioned on the resonant column 8 and the symmetrical probe 7, and are used for adjusting the coupling between the resonant frequency of the filter and the resonant cavity. A metal gasket 15 is arranged between the debugging screw 14 and the upper cover 9, and the top of the debugging screw 14 is fastened to the cover plate 9 through a fastening nut 16. The larger the diameter of the tuning screw 14, the greater the length that extends into the resonant cavity, and the lower the resonant frequency.

The order of assembly of the filter of this embodiment is:

Firstly, the periodic pin arranging wall 5 is pressed into the pin arranging seat 4 to form a complete pin arranging whole, and then the pin arranging whole, the grounding feed probe 61, the coupling reinforcing block 62, the PCB symmetrical probe 7 and the resonant column 8 are welded into the PCB grounding plate 2 through the processes of reflow soldering and the like, so that the core part of the filter structure is formed; at the same time, the input/output connector 12 is soldered into the input/output PCB 11 by a reflow soldering process or the like to form an input/output PCB whole, and then the PCB 11 whole is assembled into the metal cover plate 9 together with the debugging screw 14, the metal gasket 15, the fastening nut 16 and the like to form a cover plate whole; finally, the core part and the cover plate of the filter structure are integrally fastened together in contact with the outer cavity 3 through the fastening screw 1, the fastening screw 10 and the fastening screw 14, and the input/output PCB 11 and the ground feed probe 61 in the core part of the filter structure are soldered together (as shown in fig. 6), thereby completely constituting the entire filter structure.

The filter structure of the present invention actually includes two identical filters 101, namely, a first filter and a second filter, each having four single resonators 18 therein, as shown in fig. 2.

The implementation principle of the filter is as follows:

Referring again to fig. 5, the periodic pin header 5 is first soldered with the PCB ground plane 2 of the RF 4. In theory, periodic pin header 5 forms an artificial magnetic conductor surface (AMC) 103 in the top view of the front side (i.e., the top of the pin header structure), while an artificial electromagnetic soft surface (electromagnetic soft surface) 104 is formed on the pin header side. Wherein with respect to the artificial magnetic conductor surface (ARTIFICIAL MAGNETIC Conduct, AMC): the ideal magnetic conductor surface has high impedance and zero reflection phase. Since an ideal magnetic conductor does not exist in nature, a conductor surface that achieves high impedance and zero reflection phase characteristics similar to a surface by artificially modulating a metamaterial structure is called an artificial magnetic conductor surface.

Artificial electromagnetic soft surface: the electromagnetic soft surface is one of metamaterials, and has two characteristics, namely, the incident reflection phase of the plane wave with TE polarization is zero, and the incident reflection phase of the plane wave with TM polarization is 180 degrees; the other is electromagnetic wave energy propagation in a specific polarization direction that can block its surface. These two characteristics may be referred to as a reflection phase bandgap characteristic and a surface wave bandgap characteristic, respectively. Electromagnetic soft surfaces are also not present in nature, but can be achieved by modulating artificial metamaterials and are therefore also artificial electromagnetic soft surfaces.

When the height of the outer cavity 3 is higher than the height between the top of the pin-array wall 5 and the PCB grounding plate 2 and is not more than one fourth of the working wavelength, at this time, the metal cover plate 9 is fastened to the outer cavity 3, and as an air or medium gap with the thickness of not more than one fourth of the wavelength is left between the metal cover plate 9 and the pin-array wall 5, a band gap structure 102 (shown in fig. 4-5) is formed, the band gap structure 102 forms an electromagnetic band gap with enough broadband for electromagnetic waves, and electromagnetic waves with various polarization directions cannot be transmitted in the gap within the bandwidth range of the band gap, namely, the electromagnetic waves are completely cut off in the gap; in addition, due to the artificial electromagnetic soft surface 104 formed on the side of the pin header, the electromagnetic soft surface has a characteristic of blocking the propagation of electromagnetic waves in all polarization directions, so that the electromagnetic waves cannot penetrate the side of the pin header. Thus, electromagnetic waves can only be reflected back into and be trapped in the cavity portion enclosed by the pin header, either in the gap at the top of the pin header or at the sides of the pin header. When the size of the metal resonant pillars 8 in each single cavity 18 (as the box enclosed by the dashed lines in fig. 2) in the cavity is adjusted to a suitable size according to the specific resonant frequency of the resonant cavity, the single cavity 18 enclosed by the pin header 5, the PCB ground plane 2 and the metal cover plate 9 resonates at the operating frequency to form a resonant cavity. The energy is transferred between the resonant cavities through the coupling device, the coupling enhancing block 62 plays a role of enhancing the energy coupling between the resonant cavities, and the input-output grounding feed probe 61 transmits the signals of the first resonant cavity 18 and the last resonant cavity 18 to the connector 12 of the input-output PCB in a capacitive coupling mode, and the connector 12 is connected with the outside, so that a complete filter structure is formed. The coupling means here refers to a coupling enhancement block 62, the coupling between the cavities of the cavity filter is typically magnetic, and the introduction of a grounded metal coupling enhancement block 62 can enhance the magnetic field amplitude at the coupling location, thereby enhancing the coupling between the cavities.

In the filter, when a useful signal is in the passband of the filter, the signal can pass through the filter unimpeded, while on a frequency band far away from the resonance frequency, energy is greatly attenuated by the filter and cannot pass through the filter, which is also the reason that the filter can effectively filter out-of-band clutter.

Fig. 11 shows a cell bandgap simulation of a periodic pin 50, ground plate 2 and cover plate 9. The curve in the figure shows that the forbidden band is formed at 4-7GHz, so that the requirement that the filter works at 5-6GHz WIFI frequency band can be met, and most electromagnetic energy is bound in the cavity from electromagnetic energy in the single cavity in the right figure, and little energy can be radiated outwards through the periodic pin 50, the grounding plate 2 and the cover plate 9.

Fig. 12 is a graph of WIFI 36 channel filter results based on an array process design. The curve is an input-output response curve of the filter, and reflects the conditions of insertion loss, out-of-band rejection and return loss of the filter. Wherein the peak-up curve reflects insertion loss and out-of-band rejection, and the peak-down curve is the return loss curve. The invention realizes the WIFI filter with good performance, wherein the insertion loss is smaller than 1.3dB, the out-of-band rejection of 5.3-5.8GHz is smaller than 43dB, and the return loss is smaller than 20 dB.

It will be appreciated that in the above embodiments, the number and arrangement of the pins may be adjusted, and accordingly, the metallized vias 20 on the PCB ground plane and the corresponding vias on the pin header may be adjusted accordingly. The number and shape of the pins of each element can be properly adjusted. The number, structure and arrangement of the feed probes, the coupling reinforcing blocks, the symmetrical probes, the resonant columns, the input/output connectors and/or the debugging screws can be adjusted according to the requirement of the specific filter filtering performance.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A filter structure comprising a ground plate as an underlying ground and a cover plate as an overlying ground; the method is characterized in that: a pin arranging wall formed by periodically arranging pins is arranged between the grounding plate and the cover plate; the bottom of the pin-array wall is arranged on the grounding plate and is electrically connected with the grounding plate, and a gap is formed between the top of the pin-array wall and the cover plate to form an artificial band gap structure;

The grounding plate, the pin header wall and the cover plate jointly enclose a plurality of resonant cavities of the filter, and the filter structure is separated to form a plurality of filters; each filter is provided with a pair of grounding feed probes, the grounding feed probes carry out coupling feed on the filter, and the energy of the filter is conducted to the outside of the filter in a capacitive coupling mode; a resonant column is arranged in the resonant cavity; a coupling enhancement block is arranged in the filter; two adjacent filters in the plurality of filters are respectively provided with a probe to form a pair of symmetrical probes, and the symmetrical probes form symmetrical zero points in the filters; the filter structure also comprises a needle arrangement seat, and the periodic needle arrangement of the needle arrangement wall is connected into a whole by the needle arrangement seat; the top of the pin-arranging wall forms an artificial magnetic conductor surface, the side surface of the pin-arranging wall forms an artificial electromagnetic soft surface, and an interception mode is formed for the electromagnetic wave in transmission, so that the electromagnetic wave cannot penetrate through the electromagnetic wave.

2. The filter structure of claim 1, wherein: the interval between the top of the pin-arranging wall and the cover plate is not more than one quarter of the working wavelength, and the gap between the side surfaces of the pins forms the artificial electromagnetic soft surface; the cover plate is a metal cover plate and/or a PCB (printed circuit board); the pin header is a metal thin rod; the grounding plate is connected with the pin header through a reflow soldering process; the grounding plate is a PCB grounding plate, copper plated or silver plated metal sheet; the top of the row needle is provided with a mushroom-like head patch to reduce the size.

3. The filter structure of claim 1, wherein: an input/output PCB is arranged at the top of the filter; the bottom of the grounding feed probe is electrically connected with the grounding plate and grounded, and the top of the grounding feed probe is electrically connected with the input/output PCB; the input/output PCB is assembled on the outer side of the top of the cover plate, and the top end of the ground feed probe penetrates through the cover plate and a via hole arranged on the input/output PCB; the input/output PCB is provided with an input/output connector which is electrically connected with the outside, and the input/output connector is electrically connected with the top end of the grounding feed probe through a microstrip line; the pair of ground feed probes are respectively positioned in the first resonant cavity and the last resonant cavity, and the signals of the first resonant cavity and the last resonant cavity are transmitted to the input/output PCB in a capacitive coupling mode to be connected with the outside; the resonant cavities are mutually coupled; the coupling enhancement block is arranged on the grounding plate and is electrically connected with the grounding plate; the resonance column is arranged on the grounding plate and is electrically connected with the grounding plate; the coupling enhancement block is arranged between the adjacent resonant cavities; two probes of the symmetrical probes are respectively arranged between the first resonant cavity and the last resonant cavity of each of the two adjacent filters to realize symmetrical zero points; each resonant cavity is provided with a resonant column at the center.

4. A filter structure as claimed in claim 3, characterized in that: the coupling enhancement block comprises a horizontal flaky body, and pins are vertically arranged downwards at two sides of the horizontal flaky body; the symmetrical probes are of a T-shaped PCB structure, wherein the part with the electric effect is positioned at the top of the T-shaped structure, the part without the electric effect is positioned at the bottom, the bottom extends downwards to form pins, and no electric connection exists between the pins at the top and the bottom of the PCB structure; the symmetrical probes are vertical slices; the grounding feed probe comprises a vertical body, wherein the vertical body is in a vertical sheet shape, the vertical body extends upwards to form an upper pin, the upper pin penetrates through the cover plate to be connected with the input/output PCB, and the vertical body extends downwards to form a grounding pin; the pins of the coupling enhancement block, the pins of the symmetrical probes and the grounding pins of the grounding feed probes are welded on the grounding plate.

5. The filter structure of claim 4, wherein: the coupling enhancement block comprises a horizontal sheet-shaped body, a pair of opposite pins and a third pin, wherein the horizontal sheet-shaped body of the coupling enhancement block extends downwards and vertically to form three pins, the three pins extend downwards from two ends of the same side of the horizontal sheet-shaped body to form a pair of opposite pins, the middle part of the opposite side extends downwards and vertically to form the third pin, and the pins are arranged in a step shape; the pins of the symmetrical probes extending downwards are stepped; the upright body of the feed probe extends upwards to form a step-shaped upper pin, and the upper pin penetrates through the cover plate, is inserted into a through hole arranged on the input/output PCB and is welded to the input/output PCB; the bottom of the feed probe body is provided with three grounding pins, the middle of the feed probe body downwards extends to form a narrower middle pin, two sides of the feed probe body laterally and vertically form a pair of left and right pins, and the grounding pins are in a step shape; a plurality of coupling enhancement blocks are arranged in the same filter, and one sides of the coupling enhancement blocks, provided with a pair of pins, are opposite; the grounding plate is provided with through holes, and pins of the coupling enhancement block, pins of the symmetrical probes and grounding pins of the grounding feed probes are inserted into the corresponding through holes and welded on the grounding plate.

6. The filter structure of claim 5, wherein: the filter structure further comprises an outer cavity serving as a middle ground, and the grounding plate and the cover plate are respectively fastened at the bottom and the top of the outer cavity; the inner wall of the outer cavity is vertically provided with a plurality of screw grooves, fastening screws penetrate through the grounding plate and penetrate upwards into the lower sections of the screw grooves to be fastened, the fastening screws penetrate through the cover plate and penetrate downwards into the upper sections of the screw grooves to be fastened, and the inner wall of the outer cavity is further provided with vertical ribs; a plurality of debugging screws for adjusting the coupling between the resonant frequency of the filter and the resonant cavity are arranged on the cover plate, and penetrate through the cover plate and downwards extend into the resonant cavity; the bottom end of the debugging screw is positioned above the coupling enhancement block, the symmetrical probe and the resonance column; the needle arrangement seat is arranged in the outer cavity and is abutted and fixed by vertical ribs on the inner wall of the outer cavity.

7. The filter structure of claim 6, wherein: the pin array wall, the grounding feed probe, the coupling reinforcing block, the symmetrical probe and the resonant column are welded into the grounding plate to form a core part of the filter structure; the input and output connectors are welded into the input and output PCBs to form an input and output PCB whole, and the input and output PCB whole and the debugging screw are assembled on the cover plate to form a cover plate whole; the core part and the cover plate of the filter are respectively fastened together in contact with the outer cavity by fastening screws, and the input/output PCB and the feed probe in the core part of the filter are welded together to form a filter structure; the debugging screw is fastened to the cover plate by means of a metal gasket and a fastening nut.

8. The filter structure of any of claims 1-7, wherein: the needle arrangement seat is a connecting structure made of non-conductive medium material; the pin row wall is pressed into the pin row seat so as to connect the periodic pin row into an integral structure; the needle arrangement seat is provided with perforations, and each needle arrangement seat passes through one perforation to be fixedly connected; the grounding plate is provided with a metallized via hole, the metallized via hole is arranged corresponding to the periodic pin header and/or the perforation on the pin header, and the bottom end of each pin header is inserted into one metallized via hole after passing through the perforation on the pin header and welded on the grounding plate; in each filter, the pin-arranging wall comprises a pin-arranging annular array positioned at the periphery and a pin-arranging separation array positioned at the center of the filter, and the pin-arranging separation array separates one filter into a plurality of resonant cavities; two adjacent filters are parallel and adjacent with one side of the pin array.

9. The filter structure of claim 8, wherein: the separation array comprises a pin row crisscross array formed by a plurality of transverse rows and vertical rows of pin rows in a crossed arrangement; the periodic row pins are aligned with the vertical rows from one side of the annular array to form an extended vertical row array, the extended vertical row array is separated from the vertical row pins of the crisscross array by a gap, and one of the pair of symmetrical probes is transversely arranged in the gap; the crisscross pin array divides each filter into four resonant cavities, and the resonant cavities in two adjacent filters are symmetrically arranged.

10. The filter structure of claim 9, wherein: the needle arrangement seat in the two adjacent filters comprises a non-conductive medium frame body with an integral structure, a plurality of circles of perforations are arranged on the frame body, and the needle arrangement annular array is correspondingly pressed into the circles of perforations; the needle arrangement seat also comprises a medium separation section, the medium separation section is connected with the relative bottom edge of the medium frame body, the medium separation section is provided with a plurality of vertical row perforations, and the row pairs positioned on the side edges of the two annular arrays which are adjacent in parallel are correspondingly pressed into the plurality of vertical row perforations to form an integral structure; the medium separation section divides the needle arrangement seat into two needle arrangement seat units, corresponding to each filter, the center of each needle arrangement seat unit is provided with a crisscross medium body, the crisscross medium body is provided with a plurality of transverse rows and vertical rows of perforations which are arranged into a crisscross perforation arrangement, and the crisscross needle arrangement seat array is pressed into the perforations on the crisscross medium body to be connected into an integral structure; a bottom edge of the dielectric frame body extends to form a section of vertical dielectric body, and is aligned with the vertical bottom end of the cross-shaped crossed dielectric body at intervals of the gap; a plurality of vertical row perforations are arranged on the vertical dielectric body, and a vertical row array extending from the row pins is pressed into the plurality of vertical row perforations to be connected into an integral structure; the annular array of the pin header wall is a square array.

11. The filter structure of claim 9, wherein: three coupling enhancement blocks are arranged in one filter, and one of the three coupling enhancement blocks and the symmetrical probes is respectively positioned at the outer side of the cross-shaped tail end of the cross pin array and is spaced from the cross-shaped tail end by a certain gap.