CN108631029B

CN108631029B - Cavity filter

Info

Publication number: CN108631029B
Application number: CN201710177639.0A
Authority: CN
Inventors: 翁国执
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2017-03-23
Filing date: 2017-03-23
Publication date: 2021-04-27
Anticipated expiration: 2037-03-23
Also published as: CN108631029A

Abstract

A cavity filter comprising: the resonant cavity group comprises two resonant cavities, a separation part is arranged between the two resonant cavities, and the separation part is provided with an adjusting channel penetrating through the two resonant cavities; the cover plate is connected with the shell to cover the resonant cavity group; the resonance component comprises a resonance tube, a resonance cap and a resonance adjusting screw, wherein the resonance tube and the resonance cap are mutually connected, the resonance adjusting screw is adjustably arranged in the resonance tube, the resonance tube is arranged on the inner wall of the resonance cavity, and the resonance cap is opposite to the cover plate; and a coupling adjustment component for reducing the amount of magnetic coupling between the two resonant cavities and enhancing the amount of electrical coupling between the two resonant cavities. The cavity filter is characterized in that the resonance adjusting screw and the coupling adjusting component are embedded in the bottom of the shell, so that the cavity filter is convenient to adjust; the cover plate is not provided with any adjusting structure, so that the thickness of the cover plate is reduced, the size is simplified, the material is saved, and the cost is reduced.

Description

Cavity filter

Technical Field

The invention relates to the technical field of filters, in particular to a cavity filter.

Background

A typical cavity filter is provided with a coupling adjustment structure for adjusting the frequency of the filter and the amount of electrical coupling between the cavities, such as a resonance adjustment screw and a coupling adjustment screw, which are mostly disposed above the cover plate. In order to install and fix the resonance adjusting screw and the coupling adjusting screw, the cover plate needs to have certain thickness, so that the overall size of the cavity filter is increased; and set up resonance adjusting screw and coupling adjusting screw on the apron for apron upper surface unevenness, occupation space, it is inconvenient to use, and influences pleasing to the eye.

Disclosure of Invention

Accordingly, there is a need for a cavity filter with coupling adjustment structure at the bottom of the housing to reduce the size of the cavity filter and facilitate adjustment.

A cavity filter comprising: the resonant cavity group comprises two resonant cavities, a separation part is arranged between the two resonant cavities, and the separation part is provided with an adjusting channel penetrating through the two resonant cavities;

the cover plate is connected with the shell to cover the resonant cavity group;

the resonance component comprises a resonance tube, a resonance cap and a resonance adjusting screw, wherein the resonance tube and the resonance cap are mutually connected, the resonance adjusting screw is arranged in the resonance tube, the resonance tube is arranged on the inner wall of the resonance cavity, and the resonance cap is opposite to the cover plate; and

the coupling adjusting assembly is used for reducing the magnetic coupling amount between the two resonant cavities and enhancing the electric coupling amount between the two resonant cavities, and comprises a coupling fixing structure and a coupling adjusting structure arranged on the coupling fixing structure, the coupling fixing structure is fixedly arranged on the separating part, and the coupling adjusting structure extends out of the adjusting channel.

Furthermore, the cavity filter also comprises a capacitor loading ring, the resonance cap is provided with a concave part, and the capacitor loading ring is fixedly arranged on the cover plate and extends into the concave part; the coupling fixing structure comprises a separation wall, the coupling adjusting structure comprises a coupling adjusting screw and an electric coupling sheet, and the separation wall is fixedly arranged on the separation part; the isolation wall comprises a first fixing seat and a second fixing seat, the electric coupling piece is fixed on the first fixing seat, one end of the coupling adjusting screw is fixed on the second fixing seat, and the other end of the coupling adjusting screw extends out of the second fixing seat and is located in the adjusting channel.

Further, the electric coupling piece is fixed to the first fixed seat through a fastener, and a gasket is arranged between the electric coupling piece and the first fixed seat; the electric coupling piece comprises a bottom plate, two symmetrical extending arms and two symmetrical spacers, wherein the two symmetrical extending arms extend out from the side edge of the bottom plate, the two symmetrical extending arms respectively extend into the two resonant cavities and respectively extend to the lower part of the resonant cap so as to form a capacitor with the resonant cap, and the coupling adjusting screw extends out of one end of the second fixing seat and is positioned between the two symmetrical spacers.

Furthermore, a first opening and a second opening are respectively arranged on two opposite sides of the bottom plate, the two symmetrical spacers are respectively arranged on two sides of the first opening, and the two symmetrical extending arms are respectively arranged on two sides of the second opening; the two symmetrical isolation sheets are perpendicular to the bottom plate, and the two symmetrical extending arms are parallel to the bottom plate.

Furthermore, the partition wall further comprises a first partition plate and a second partition plate, the first fixing seat, the second fixing seat and the second partition plate are sequentially connected, the first fixing seat and the second fixing seat are arranged in a ladder structure, and the first fixing seat is higher than the second fixing seat.

Furthermore, the bottom of the isolation wall is embedded in the shell, and the coupling adjusting screw penetrates through the bottom of the shell and is mounted to the second fixed seat through a threaded structure; and rotating the coupling adjusting screw forward and backward to adjust the length of the coupling adjusting screw extending out of the second fixed seat, so as to adjust the electric coupling quantity between the two resonant cavities.

Further, the fastener and the gasket are both made of insulating materials.

Furthermore, the first isolation plate is provided with a positioning column, and the positioning column and the second fixing seat are consistent in height and are respectively abutted to the cover plate.

Furthermore, the coupling fixing structure comprises a third fixing seat, the coupling adjusting structure comprises a coupling adjusting screw, the third fixing seat is fixedly arranged on the partition part, one end of the coupling adjusting screw is fixed on the third fixing seat, and the other end of the coupling adjusting screw extends out of the third fixing seat and is positioned in the adjusting channel; the side edge of the resonance cap adjacent to the coupling adjusting screw is provided with a notch, and the notch is opposite to the coupling adjusting screw.

Further, the resonance cap is approximately circular, the gap is a section of circular arc, and the arc center of the circular arc is located on the axial direction of the coupling adjusting screw.

According to the cavity filter, the resonance component and the coupling adjusting component are embedded in the bottom of the shell, so that an adjusting structure is not exposed on the outer surface of the shell, and the bottom of the shell is kept flat, so that the appearance size of the cavity filter is reduced, the purpose of reducing the size is achieved, and the cavity filter is convenient to adjust; the cover plate is not provided with any adjusting structure, so that the thickness of the cover plate is reduced, the material is saved, and the cost is reduced. The cavity filter also increases the frequency debugging range of the coupling adjusting screw by changing the shape of the resonance cap and arranging the electric coupling piece, and improves the performance of the cavity filter.

Drawings

Fig. 1 is an exploded view of a cavity filter according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a housing of a cavity filter according to an embodiment of the invention.

Fig. 3 is an exploded view of the coupling adjustment assembly of the cavity filter of fig. 1.

Fig. 4 is an exploded view of the resonator component of the cavity filter of fig. 1.

Fig. 5 is an assembled perspective view of fig. 1 with the cover removed.

Fig. 6 is an exploded view of a cavity filter according to another embodiment of the present invention.

Fig. 7 is an assembled perspective view of fig. 6 with the cover removed.

Description of the main elements

Cavity filter 100

Cover plate 110

Capacitive loading ring 120

Resonant assembly

130, 160

Resonator tubes

133, 163

Fixing post 1632

Sleeving connection column 1631

Resonant

cap

132, 162

Cap

1321, 1621

Recesses

1322, 1622

Through holes 1323, 1623

Step 1324

Notch 1624

Resonance adjusting

screws

131, 161

Coupling adjustment assemblies 140, 170

Partition wall 143

First separator plate 1431

Positioning post 1435

Screw

holes

1436, 1437, 1331

Second separator plate 1434

First fixing seat 1432

Second fixed seat 1433

Third fixing seat 171

Coupling adjusting screws

142, 172

Electric coupling sheet 141

Bottom plate 1410

First opening 1413

Second opening 1414

Bayonet 1415

Locking port 1416

Spacer 1412

Reach out arm 1411

Gasket 145

Shim through hole 1451

Fastener 144

Housing 150

Resonant cavity 151

Partition 152

Adjusting channel 153

Housing bottom wall 154

Resonant cavity group 180

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

The first implementation mode comprises the following steps:

fig. 1 shows an exploded view of a cavity filter 100 according to an embodiment of the present invention. In the figure, the cavity filter 100 includes a cover plate 110, a capacitive loading ring 120, a resonant assembly 130, a coupling adjustment assembly 140, and a housing 150, the resonant assembly 130 includes a resonance adjustment screw 131, a resonance cap 132, and a resonant tube 133, the resonance cap 132 is sleeved on the resonant tube 133, and the resonance adjustment screw 131 is connected to the resonant tube 133 through a threaded structure; the coupling adjustment assembly 140 comprises an electric coupling piece 141, a coupling adjustment screw 142 and a partition wall 143, wherein the electric coupling piece 141 is provided with two symmetrical extending arms 1411, the electric coupling piece 141 is fixed to the partition wall 143 through a fastener 144, a gasket 145 is further arranged between the electric coupling piece 141 and the partition wall 143, and the coupling adjustment screw 142 is connected to the partition wall 143 through a threaded structure; the shell 150 comprises two symmetrical resonant cavities 151 formed inside the shell 150, a partition part 152 is arranged between the two resonant cavities 151, and the partition part 152 is provided with an adjusting channel 153 which penetrates the two resonant cavities; the capacitive loading ring 120 is fixed on the inner side of the cover plate 110 and faces the resonant assembly 130, the isolation wall 143 is fixed on the bottom wall of the isolation channel 153 and abuts against the partition portion 152, the resonant tube 133 is fixed on the bottom wall 154 of the housing (see fig. 2), and the cover plate 110 covers the housing 150 to seal the resonant cavity 151.

Referring to fig. 2, in the present embodiment, preferably, the housing 150 has a resonant cavity group 180, that is, the housing has two resonant cavities 151, in other embodiments, the housing 150 may have a plurality of resonant cavity groups 180, each resonant cavity group 180 may be parallel or perpendicular to each other, but the resonant cavities 151 of two adjacent resonant cavity groups 180 cannot be connected; the bottom of the partition wall 143 is fitted to the bottom of the adjustment channel 153, both sides thereof abut against the partition 152, and the top thereof abuts against the inner side of the cover plate 110, and the bottom of the resonator tube 133 is integrally formed with the bottom wall 154 of the housing 150, in other embodiments, the partition wall 143 may be welded to the bottom of the adjustment channel 153, and the bottom of the resonator tube 133 may also be welded to the bottom wall 154 of the housing 150; the cover plate 110 and the housing 150 are connected by a screw structure (not shown), for example, in an embodiment, a fixing lug may be led out from the housing 150, a screw hole and a positioning post may be disposed on the lug, correspondingly, a screw hole and a positioning hole may be disposed at a corresponding position of the cover plate 110, the cover plate 110 and the housing 150 are accurately aligned by matching the positioning post and the positioning hole, and finally, a screw is installed to the screw hole of the fixing lug of the housing 150 and the cover plate 110 and the housing 150 are locked. In order to facilitate the installation and adjustment of the resonance adjusting screw 131 and the coupling adjusting screw 142, the resonance tube 133 and the separating wall 143 are provided with threaded holes (not shown) penetrating through the bottom of the housing 150, and the resonance adjusting screw 131 and the coupling adjusting screw 142 are screwed into the resonance tube 133 and the separating wall 143 from the bottom of the housing 150, respectively, in other embodiments, the resonance tube 133 and the separating wall 143 at the bottom of the housing 150 may be disposed in a recessed structure, but other positions at the bottom of the housing 150 may be disposed in a plane, so that the screw holes of the resonance tube 133 and the separating wall 143 are exposed in the recessed structure to install the resonance adjusting screw 131 and the coupling adjusting screw 142.

Fig. 3 is an exploded view of the coupling adjustment assembly 140 shown in fig. 1, in which the electric coupling piece 141 includes a bottom plate 1410, two symmetrical protruding arms 1411 extending from the side edges of the bottom plate 1410, and two symmetrical spacers 1412, the bottom plate 1410 has a first opening 1413 and a second opening 1414, the second opening 1414 includes a bayonet 1415 and a locking opening 1416 that are connected to each other, the bayonet 1415 is used for positioning, the locking opening 1416 is used for locking, the two symmetrical spacers 1412 are respectively disposed on two sides of the first opening 1413, and the two symmetrical protruding arms 1411 are respectively disposed on two sides of the second opening 1414; two symmetrical spacers 1412 are positioned perpendicular to the base plate 1410 and two symmetrical projecting arms 1411 are positioned parallel to the base plate 1410. The isolation wall 143 includes a first isolation plate 1431, a first fixing seat 1432, a second fixing seat 1433 and a second isolation plate 1434 which are sequentially connected, the first fixing seat 1432 and the second fixing seat 1433 are arranged in a ladder structure, the first fixing seat 1432 is higher than the second fixing seat 1433, the first isolation plate 1431 is provided with a positioning column 1435, and the positioning column 1435 is as high as the second isolation plate 1434; the coupling adjusting screw 142 is connected to the second fixing seat 1433 through a screw hole 1437, and the length of the coupling adjusting screw extending out of the second fixing seat 1433 is adjustable; the first holder 1432 is provided with a screw hole 1436 to be engaged with the fastener 144. In assembly, the spacer 145 is placed on the first fixing seat 1432, the bayonet 1415 of the electric coupling piece 141 is clamped into the positioning column 1435, the bottom plate 1410 is placed on the spacer 145, and finally the fastening member 144 passes through the locking opening 1416 and the spacer through hole 1451 in sequence and is matched and locked with the screw hole 1436, so that the electric coupling piece 141 and the separation wall 143 are fixed together, and at this time, the coupling adjusting screw 142 is located between the two separation pieces 1412 and just below the first opening 1413. In the present embodiment, the fastening member 144 is a screw, and the fastening member 144 and the gasket 145 are made of an insulating material, such as plastic, rubber, ceramic, etc.

Fig. 4 is an exploded view of resonator assembly 130 of fig. 1, in which resonator cap 132 includes a cap 1321, a recess 1322 formed in a central portion of cap 1321, and a through hole 1323 formed in recess 1322, through hole 1323 has a step 1324, and cap 1321 has a substantially rectangular shape with rounded corners; the resonator tube 133 is provided with a screw hole 1331 in the middle thereof, and the resonance adjusting screw 131 is mounted in the screw hole 1331, and the length of the screw extending out of the resonator tube 133 is adjustable. When the resonator tube 133 is assembled, the resonator tube 133 passes through the through hole 1323 and is clamped on the step 1324, the resonator tube 133 and the through hole 1323 are in interference fit to fix the resonator tube 133 to the resonator cap 132, the resonance adjusting screw 131 passes through the through hole 1323 and can freely stretch and retract, and in other embodiments, the resonator cap 132 and the resonator tube 133 can be connected and fixed in a welding manner.

Referring to fig. 1, 3 and 4, when the housing 150 and the cover plate 110 are assembled together, the two capacitive loading rings 120 fixed to the inner side of the cover plate 110 respectively extend into the recesses 1322 of the two resonant caps 132 but do not contact with the recesses 1322, so as to respectively form loading capacitors in the two resonant cavities 151, and the frequency of the cavity filter 100 is tuned by the resonant adjusting screws 131 arranged on the resonant tubes 133. The positioning post 1435 and the second isolation plate 1434 of the coupling adjustment assembly 140 respectively abut against the inner side of the cover plate 110, and the coupling adjustment screw 142 extending from the bottom of the housing 150 and fixed on the second fixing seat 1433 is grounded; referring to fig. 5, the two extending arms 1411 of the electric coupling plate 141 respectively extend into the lower portions of the two resonant caps 132 to form capacitors with the resonant caps 132, and the length of the coupling adjustment screw 142 extending out of the second fixing seat 1433 is adjusted to adjust the ground capacitance of the electric coupling plate 141, so as to adjust the electric coupling between the two resonant cavities 151. According to the invention, the coupling adjusting component 140 is arranged between the two resonant cavities 151 of the cavity filter 100, so that the magnetic coupling between the two resonant cavities 151 is effectively reduced, and the electric coupling quantity between the two resonant cavities 151 is enhanced.

The second embodiment:

fig. 6 is an exploded view of a cavity filter 100 according to another embodiment of the present invention. In the figure, the cavity filter 100 includes a cover plate 110, a resonance component 160, a coupling adjustment component 170, and a housing 150, the resonance component 160 includes a resonance adjustment screw 161, a resonance cap 162, and a resonance tube 163, the resonance cap 162 is sleeved on the resonance tube 163, and the resonance adjustment screw 161 is connected to the resonance tube 163 through a threaded structure; the coupling adjustment assembly 170 includes a third fixing seat 171 and a coupling adjustment screw 172, and the coupling adjustment screw 172 is adjustably mounted on the third fixing seat 171 through a threaded structure; the third fixing seat 171 is fixed at the bottom of the adjusting channel 153, the resonator tube 163 is fixed at the bottom wall 154 of the casing 150 (see fig. 2), and the cover plate 110 covers the casing 150 to seal the resonant cavity 151.

Referring to fig. 7, in the present embodiment, the resonant cap 162 includes a cap body 1621, a concave portion 1622 disposed in the middle of the cap body 1621, and a through hole 1623 disposed in the concave portion 1622, wherein the cap body 1621 is substantially circular, and a notch 1624 is disposed on one side edge thereof; the resonant tube 163 is substantially in a stepped column shape with a thin top and a thick bottom, and includes a fixing column 1632 and a sleeved column 1631, the diameter of the sleeved column 1631 is smaller than that of the fixing column 1632, the fixing column 1632 is fixed to the bottom wall 154 of the housing 150 (please refer to fig. 2), the sleeved column 1631 passes through the through hole 1623 and is in interference fit with the through hole 1623, so that the resonant tube 163 and the resonant cap 162 are fastened together, and the resonant adjusting screw 161 passes through the through hole 1623 and can be adjusted in a freely telescopic manner; the third fixing seat 171 is disposed at a middle position of the bottom of the adjustment channel 153, and the coupling adjustment screw 172 extends from the third fixing seat 171 into the adjustment channel 153, preferably, the bottom of the third fixing seat 171 is embedded into the bottom of the adjustment channel 153, the resonator tube 163 and the third fixing seat 171 are provided with threaded holes (not shown) penetrating through the bottom of the housing 150, and the resonance adjustment screw 161 and the coupling adjustment screw 172 are screwed into the resonator tube 163 and the third fixing seat 171 from the bottom of the housing 150, respectively. In other embodiments, the bottom of the housing 150 may be provided with the resonator tube 163 and the third fixing base 171 at positions in a recessed structure, but other positions of the bottom of the housing 150 may be provided in a plane so that screw holes of the resonator tube 163 and the third fixing base 171 are exposed in the recessed structure to mount the resonance adjusting screw 161 and the coupling adjusting screw 172.

As shown in fig. 6 and 7, the notches 1624 of the two resonant caps 162 are symmetrically arranged around the coupling adjustment screw 172, the notches 1624 are arcs, and the arc centers of the arcs are in the axial direction of the coupling adjustment screw 172. In the present embodiment, by forming the cap 1621 of the resonant cap 162 in a circular shape and forming a notch 1624 at the edge thereof, the resonant frequency of the single resonant cavity 151 changes by only one percent, but the coupling bandwidth (coupling bandwidth) is almost doubled, thereby facilitating the production of the cavity filter 100 and facilitating the tuning of the return loss (return loss) and the pass band (bandwidth). For filters that typically use a circular resonator cap 162, the coupling adjustment screw 161 can only adjust 5.5MHz over a 6mm range of travel, but with this modification, the coupling bandwidth can be increased to 10MHz while the resonant frequency of a single resonator 151 rises from 2170MHz to 2190MHz by only about 1% (20MHz), a variable that can be accommodated by adjusting the coupling adjustment screw 161 or modifying the dimensions of other components within the resonator.

In the cavity filter provided by the invention, the

resonance components

130 and 160 and the

coupling adjusting components

140 and 170 are embedded at the bottom of the shell 150, so that the outer surface of the shell 150 has no exposed adjusting structure, and the bottom of the shell 150 is kept flat, thereby reducing the appearance size of the cavity filter 100, achieving the purpose of reducing the size and being convenient to adjust; the cover plate 110 is not provided with any adjusting structure, so that the thickness of the cover plate is reduced, the material is saved, and the cost is reduced. The cavity filter 100 also improves the performance of the cavity filter 100 by changing the shape of the resonant cap 162 and providing the electric coupling tab 141 to increase the frequency tuning range of the coupling adjustment screws 142 and 172.

It will be apparent to those skilled in the art that other corresponding changes and modifications can be made according to the actual needs created by the inventive arrangements and inventive concepts herein, and such changes and modifications are intended to fall within the scope of the appended claims.

Claims

1. A cavity filter, comprising:

the resonant cavity group comprises two resonant cavities, a separation part is arranged between the two resonant cavities, and the separation part is provided with an adjusting channel penetrating through the two resonant cavities;

the cover plate is connected with the shell to cover the resonant cavity group;

the resonance component comprises a resonance tube, a resonance cap and a resonance adjusting screw, wherein the resonance tube and the resonance cap are mutually connected, the resonance adjusting screw is arranged in the resonance tube, the resonance tube is arranged on the inner wall of the resonance cavity, and the resonance cap is opposite to the cover plate;

the coupling adjusting assembly is used for reducing the magnetic coupling amount between the two resonant cavities and enhancing the electric coupling amount between the two resonant cavities, and comprises a coupling fixing structure and a coupling adjusting structure arranged on the coupling fixing structure, wherein the coupling fixing structure is fixedly arranged on the separating part, and the coupling adjusting structure extends out of the adjusting channel; and

the resonance cap is provided with a concave part, and the capacitance loading ring is fixedly arranged on the cover plate and extends into the concave part; the coupling fixing structure comprises a separation wall, the coupling adjusting structure comprises a coupling adjusting screw and an electric coupling sheet, and the separation wall is fixedly arranged on the separation part; the partition wall includes first fixing base and second fixing base, the electric coupling piece is fixed in first fixing base, coupling adjusting screw one end is fixed in the second fixing base, the other end stretch out in the second fixing base is located the adjustment passageway, the electric coupling piece includes the bottom plate, two symmetry that extend out from the bottom plate side stretch out arm and two symmetry spacers, two symmetry stretch out the arm respectively stretch into two resonant cavities and extend to respectively the resonance cap below with the resonance cap forms electric capacity.

2. The cavity filter according to claim 1, wherein the electric coupling plate is fixed to the first fixing base by a fastener, a spacer is disposed between the electric coupling plate and the first fixing base, and the coupling adjustment screw extends out of one end of the second fixing base and is located between the two symmetrical spacers.

3. The cavity filter of claim 2, wherein said bottom plate has a first opening and a second opening on opposite sides thereof, said two symmetric spacers are disposed on opposite sides of said first opening, and said two symmetric arms are disposed on opposite sides of said second opening; the two symmetrical isolation sheets are perpendicular to the bottom plate, and the two symmetrical extending arms are parallel to the bottom plate.

4. The cavity filter of claim 1, wherein the partition wall further comprises a first partition plate and a second partition plate, the first fixing seat, the second fixing seat and the second partition plate are sequentially connected, the first fixing seat and the second fixing seat are arranged in a ladder structure, and the first fixing seat is higher than the second fixing seat.

5. The cavity filter of claim 4, wherein the bottom of the isolation wall is embedded in the housing, and the coupling adjustment screw penetrates through the bottom of the housing and is mounted to the second fixing seat through a threaded structure; and rotating the coupling adjusting screw forward and backward to adjust the length of the coupling adjusting screw extending out of the second fixed seat, so as to adjust the electric coupling quantity between the two resonant cavities.

6. The cavity filter of claim 2, wherein said fastener and said spacer are both dielectric.

7. The cavity filter of claim 4, wherein the first isolation plate is provided with positioning posts, and the positioning posts are in height coincidence with the second fixing seats and are respectively abutted to the cover plate.