WO2019119656A1

WO2019119656A1 - Structure for improving performance of tem all-dielectric filter

Info

Publication number: WO2019119656A1
Application number: PCT/CN2018/079545
Authority: WO
Inventors: 孟庆南; 朱晖
Original assignee: 香港凡谷发展有限公司
Priority date: 2017-12-22
Filing date: 2018-03-20
Publication date: 2019-06-27
Also published as: CN109962322A

Abstract

Disclosed in the present invention is a structure for improving performance of a transverse electromagnetic mode (TEM) all-dielectric filter. The structure comprises a dielectric cavity block, a signal shielding metal sheet, and a PCB substrate. The dielectric cavity block is soldered to the PCB substrate. One end of the signal shielding metal sheet is soldered to the dielectric cavity block, and the other end thereof is soldered to the PCB substrate. A resonance hole is disposed on the dielectric cavity block. An inner wall of the resonance hole is coated with a silver layer, and the depth of the silver layer is less than 2/3 of the depth of the resonance hole. The present invention has a simple structure and is convenient to manufacture. A silver layer having a certain depth is coated inside of a resonance hole of the existing TEM all-dielectric filter, and the height of a silver coating is controlled according to the cavity forming material and size of the hole and the aperture of the resonance hole, thereby effectively increasing a Q value of a filter while meeting the frequency requirement of a TEM all-dielectric filter. By controlling the proportion of the height of a silver coating and the height of a resonance hole, the TEM all-dielectric filter of the present invention can increase the Q value by at least 20% compared to that obtained using a traditional TEM filter.

Description

A structure for improving the performance of a TEM all-dielectric filter

Technical field

The invention relates to a base station filter, an antenna feeder type tower, a combiner and an anti-interference filter in the communication field, and particularly relates to a structure for improving the performance of a mixed TEM all-dielectric filter.

Background technique

With the rapid development of wireless mobile communication, the signal coverage of the low frequency band is larger, and the diffraction performance of the signal is better. The requirements for miniaturization of the communication equipment are increasing, especially in the field of low frequency filters, transverse electromagnetic mode ( Transverse Electromagnetic (TEM) dielectric filter is a common RF device used in wireless microphones, terminals and network equipment Printed Circuit Board (PCB). The TEM mode dielectric filter in the prior art includes The ceramic dielectric body, the conductive sintered silver paste forms a silver plating layer on the surface of the ceramic dielectric body, wherein the ceramic dielectric body functions as a dielectric resonator, and the silver plating layer forms a metal cavity. The traditional TEM mode filter does not deeply study the relationship between the cavity size, the resonant hole, the height of the silver and the Q value, and the same resonant volume and the height of the silver at the same frequency have the highest Q value even at 1000. The above differences, so it is urgent to find a Q-value-enhancing structure with different silver heights and different apertures in the same volume and the same dielectric material and the same frequency.

Summary of the invention

In view of the above drawbacks of the prior art, the object of the present invention is to solve the deficiencies of the above background art, and to provide a cavity low frequency filter to meet the requirements of a cavity dielectric filter for a higher Q value and a smaller volume.

In order to solve the above technical problem, the present invention employs a cavity mixed dielectric resonator structure for a filter, comprising a dielectric cavity block, a signal shielding metal piece, and a PCB substrate, the dielectric cavity block and the PCB Substrate soldering, one end of the signal shielding metal piece is soldered to the dielectric cavity block, and the other end is soldered to the PCB substrate, and the dielectric cavity block is provided with a resonant hole, and the inner wall of the resonant hole is plated with silver The layer has a depth of less than 2/3 of the depth of the resonant hole.

In a preferred embodiment of the present invention, when the resonant hole is a circular hole and the dielectric cavity block has a dielectric constant of 43-80 and the aperture of the resonant hole is different from the dielectric cavity block When the ratio of the length of the cavity side is 0.13-0.2, the ratio of the depth of the silver layer to the depth of the resonant hole is 0.35-0.5.

In a preferred embodiment of the present invention, when the resonant hole is a circular hole and the dielectric cavity block has a dielectric constant of 9-37 and the aperture of the resonant hole is different from the dielectric cavity block When the ratio of the length of the cavity side is 0.2-0.35, the ratio of the depth of the silver layer to the depth of the resonant hole is 0.45-0.6.

In a preferred embodiment of the present invention, when the resonant hole is a square hole and the dielectric cavity block has a dielectric constant of 43-80 and the side length of the resonant hole is opposite to the dielectric cavity block When the ratio of the length of the single cavity side is 0.13-0.2, the ratio of the depth of the silver layer to the depth of the resonant hole is 0.35-0.5.

In a preferred embodiment of the present invention, when the resonant hole is a square hole and the dielectric cavity block has a dielectric constant of 9-37 and the aperture of the resonant hole is different from the dielectric cavity block When the ratio of the length of the cavity side is 0.2-0.35, the ratio of the depth of the silver layer to the depth of the resonant hole is 0.45-0.6.

In a preferred embodiment of the present invention, the dielectric cavity block is square or rectangular, and one end face of the dielectric cavity block welded to the signal shielding metal piece is provided with an electric circuit, and the rest of the dielectric cavity block The end face is plated with a silver layer.

In a preferred embodiment of the invention, the dielectric cavity block is formed from a single piece of dielectric material, and a plurality of the resonant holes are spaced apart from the dielectric cavity block.

In a preferred embodiment of the invention, the dielectric cavity block is formed by splicing a plurality of resonant monoliths, and the resonant monolith is provided with the resonant holes.

In a preferred embodiment of the invention, the signal shielding metal sheet is L-shaped.

The invention has the advantages that the invention has the advantages of simple structure and convenient manufacture, and is plated with a certain depth of silver layer in the resonant hole of the existing TEM all-dielectric filter, and according to the cavity shape material and size of the hole and the resonant hole The aperture control controls the height of the silver so that the Q value of the filter is effectively increased while satisfying the frequency requirement of the TEM all-dielectric filter, which uses the TEM all-dielectric filter of the present invention by controlling the ratio of the height of the upper silver to the height of the resonant hole. The Q value is increased by at least 20% compared to the conventional TEM filter.

DRAWINGS

1 is a schematic diagram of a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

2 is an exploded view of a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

3 is a front elevational view showing a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

4 is a side view showing a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

5 is a top plan view showing a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

6 is a cross-sectional view along the line A-A of a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention;

7 is a schematic diagram of a dielectric cavity block for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention; (square cavity circular resonant hole)

8 is a cross-sectional view of a dielectric cavity block B-B of a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention; (square cavity square resonator hole)

9 is a schematic diagram of a dielectric cavity block for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention; (square cavity square resonator hole)

10 is a cross-sectional view of a dielectric cavity block C-C of a structure for improving the performance of a TEM all-dielectric filter according to an embodiment of the present invention; (square cavity circular resonant hole)

In the figure: 1-media cavity block, 2-signal shield metal plate, 3-PCB substrate, 4-resonant hole, 5-silver layer.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The structure of the present invention includes a dielectric cavity block 1, a signal shielding metal piece 2, and a PCB substrate 3. The dielectric cavity block 1 may be a structure diagram for improving the performance of the TEM all-dielectric filter. For dielectric materials of different dielectric constants, the dielectric cavity block 1 is soldered to the PCB substrate 3, one end of the signal shielding metal piece 2 is soldered to the dielectric cavity block 1 (to prevent signal crosstalk and leakage), and the other end is soldered to the PCB substrate 3, and the RF signal is The input and output ports of the dielectric block are connected to one end of the PCB substrate lead, and the other end of the PCB substrate can be connected to the RF connector, or can be soldered to the RF mother board through the entire PCB substrate, and connected to the LNA and the PA. A resonance hole 4 is provided on the first surface, characterized in that the inner wall of the resonance hole 4 is plated with a silver layer 5, and the depth of the silver layer 5 is smaller than 2/3 of the depth of the resonance hole 4.

When the dielectric constant is between 43 and 80, the ratio of the resonant aperture d to the single cavity length D of the dielectric cavity is between 0.13-0.2, ie d/D=0.13. -0.2; when the ratio of the upper silver height h of the resonant circular hole to the resonant hole height H is between 0.35 and 0.5, the Q value is optimal; when the dielectric constant is 9-37, the resonant aperture d and the dielectric cavity The ratio of the length D of the single cavity is between 0.2 and 0.35, that is, d/D=0.2-0.35; when the ratio of the height of the upper silver of the resonant circular hole to the height H of the resonant hole is between 0.45 and 0.6, The conventional TEM filter has a Q value higher than 20%.

When the resonant rod is square, when the dielectric constant is between 43 and 80, the ratio of the length d1 of the resonant hole to the length D of the single cavity of the dielectric cavity is between 0.13-0.2, that is, d1/D=0.13-0.2; When the ratio of the upper silver height h of the resonant square hole to the resonant hole height H is between 0.35 and 0.5, the Q value is optimal; when the dielectric constant is between 9 and 37, the resonant hole side length d1 and the dielectric cavity single The ratio of the length D of the cavity side is between 0.2 and 0.35, that is, d/D=0.2-0.35; when the ratio of the height of the upper silver of the resonant square hole to the height H of the resonant hole is between 0.45 and 0.6, compared with the conventional TEM filtering The Q value is higher than 20%.

It should be understood that the above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any one skilled in the art can easily think of changes within the technical scope disclosed by the present invention. Or, replacement, should be covered by the scope of the present invention.

Claims

A structure for improving the performance of a TEM all-dielectric filter, comprising a dielectric cavity block (1), a signal shielding metal piece (2), and a PCB substrate (3), the dielectric cavity block (1) and the PCB The substrate (3) is soldered, one end of the signal shielding metal piece (2) is soldered to the dielectric cavity block (1), and the other end is soldered to the PCB substrate (3) on the dielectric cavity block (1). A resonant hole (4) is provided, characterized in that the inner wall of the resonant hole (4) is plated with a silver layer (5), the depth of the silver layer (5) being less than 2/ of the depth of the resonant hole (4). 3.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein when said resonant hole (4) is a circular hole and said dielectric cavity block (1) has a dielectric constant of 43 -80 and the ratio of the aperture of the resonant hole (4) to the single cavity side length of the dielectric cavity block (1) is 0.13-0.2, the depth of the silver layer (5) and the resonant hole (4) The depth ratio is 0.35-0.5.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein when said resonant hole (4) is a circular hole and said dielectric cavity block (1) has a dielectric constant of 9 -37 and the ratio of the aperture of the resonant hole (4) to the length of the single cavity of the dielectric cavity block (1) is 0.2-0.35, the depth of the silver layer (5) and the resonant hole (4) The depth ratio is 0.45-0.6.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein when said resonant hole (4) is a square hole and said dielectric cavity block (1) has a dielectric constant of 43 -80 and the ratio of the side length of the resonant hole (4) to the single cavity side length of the dielectric cavity block (1) is 0.13-0.2, the depth of the silver layer (5) and the resonant hole (4) The depth ratio is 0.35-0.5.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein when said resonant hole (4) is a square hole and said dielectric cavity block (1) has a dielectric constant of 9 -37 and the ratio of the aperture of the resonant hole (4) to the length of the single cavity of the dielectric cavity block (1) is 0.2-0.35, the depth of the silver layer (5) and the resonant hole (4) The depth ratio is 0.45-0.6.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein the dielectric cavity block (1) is square or rectangular, and the dielectric cavity block (1) and the signal shielding metal are One end face of the piece (2) is provided with a circuit, and the remaining end faces of the dielectric cavity block (1) are plated with a silver layer.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein the dielectric cavity block (1) is formed as a monolithic dielectric material, and the dielectric cavity block (1) is A plurality of the resonant holes (4) are arranged at intervals.
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein the dielectric cavity block (1) is formed by splicing a plurality of resonant single blocks, and the resonant single block is provided with The resonant hole (4).
The structure for improving the performance of a TEM all-dielectric filter according to claim 1, wherein the signal shielding metal piece (2) is L-shaped.