Improved ultra-wideband board-mounted coupler device

Abstract

The present invention relates to an improved ultra-wideband board-connected coupler device, comprising a radio frequency connector, a coaxial cable, a plurality of magnetic rings, an absorbing material, a coupler circuit board, a radio frequency source circuit board and a cavity, wherein the coupler circuit board and the radio frequency source circuit board are fixedly mounted on the cavity by screws, the plurality of magnetic rings are fixedly sleeved on the coaxial cable, one end of the coaxial cable is connected to the radio frequency source circuit board and the coupler circuit, and the device fixes the magnetic rings on the coaxial cable by absorbing materials. The improved ultra-wideband board-connected coupler device of the present invention is adopted, and the coupler circuit board and the radio frequency source circuit board are directly connected by a semi-steel cable, eliminating the connector, reducing the volume and saving space. The use of absorbing materials instead of the traditional epoxy resin glue can not only fix the magnetic rings, but also absorb electromagnetic interference signals, reduce the influence of high-frequency electromagnetic signals on the port, facilitate the debugging of high-frequency indicators, and improve the technical indicators of the high-frequency end.

Description

Technical Field

[0001] The invention relates to the technical field of communication test instruments and meters, in particular to the field of a board-connected coupler device of a radio frequency front end, and specifically refers to an improved ultra-wideband board-connected coupler device. Background Art

[0002] Coupler is a very common RF module with a wide range of applications. It can be found in many instruments and meters. Commonly used couplers are divided into single directional couplers and dual directional couplers according to their functions. According to their forms, they are divided into cavity couplers, microstrip line couplers, bridge couplers, coaxial magnetic ring resistor couplers, etc. They have different application fields according to their functional characteristics.

[0003] With the vigorous development of current communication technology, especially 5G communication, a large number of communication base station facilities have been built in the wild (outdoors), such as various base stations, signal towers, etc. The construction and maintenance of these infrastructures require a lot of engineering instruments to detect system signals. In order to facilitate operators to carry and use them outdoors, these test instruments are required to be more and more miniaturized, portable, and broadband. When the instrument is small and the space is limited, the requirements for the coupler of the instrument's RF front end are getting higher and higher. This requires a miniaturized, high-performance board-mounted coupler that can be directly connected to the RF source.

[0004] Commonly used coupler devices, cavity structure coupler devices, are too large in size and can only be connected with adapter cables, and cannot be directly connected to circuit boards, which is not conducive to the miniaturization of instruments. Microstrip line couplers are generally large in size and are often used as separate coupler modules, connected to RF signals through SMA adapters. Bridge-type coupler devices, bridge structures built by resistors, can be designed directly on circuit boards, but they have high requirements for resistor accuracy, are inconvenient to debug, and are affected by the distributed parameters of lumped devices, making it difficult to widen the frequency band. Commonly used coupler devices also use coaxial magnetic ring resistor coupling. The magnetic ring on the coaxial line is often fixed with epoxy resin glue. Because of the influence of epoxy resin glue on the coupler, the coupler device with this magnetic ring fixing method has acceptable indicators in the frequency band below 4GHz. When the application frequency reaches 6GHz, the coupler device that uses epoxy resin glue to fix the magnetic ring is often not ideal in the high-frequency band due to the influence of epoxy resin. For example, the directivity is basically less than 20, which can no longer meet the test requirements of today's 5G base station construction. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide an improved ultra-wideband board-connected coupler device which has small size, good performance and a wide application range.

[0006] In order to achieve the above object, the improved ultra-wideband board-connected coupler device of the present invention is as follows:

[0007] The improved ultra-wideband board-connected coupler device has the following main features: the device includes a radio frequency connector, a coaxial cable, a plurality of magnetic rings, an absorbing material, a coupler circuit board, a radio frequency source circuit board and a cavity.

[0008] The coupler circuit board and the radio frequency source circuit board are fixedly mounted on the cavity by screws, the several magnetic rings are fixedly sleeved on the coaxial cable, one end of the coaxial cable is connected to the radio frequency source circuit board as the radio frequency signal input end, and the other end is connected to the coupler circuit. The device fixes the magnetic ring on the coaxial cable through an absorbing material, and the absorbing material has a self-adhesive side that is pasted on the PCB circuit board. The inner conductor of the coaxial cable transmits signals, and the outer shell is respectively welded to the metal ground of the coupler circuit board and the radio frequency source circuit board to form a common ground.

[0009] Preferably, the position of the magnetic ring corresponding to the cavity is a hollow structure.

[0010] Preferably, the outer diameter R2 of the coaxial cable matches the inner diameter R1 of the magnetic ring (the two are as close as possible).

[0011] Preferably, the absorbing material is used to absorb electromagnetic interference signals, improve the module's RF front-end standing wave and directivity indicators, and improve the performance of the entire device.

[0012] Preferably, the absorbing material may be a rectangular module, a square module, a triangular module, a circular module, an elliptical module, a polygonal module or an irregular module.

[0013] Preferably, the coupler circuit board includes three microstrip branch lines for debugging the port standing wave and directivity to improve the high-frequency indicators of the port.

[0014] The improved ultra-wideband board-connected coupler device of the present invention is used to directly connect the coupler circuit board and the radio frequency source circuit board through a semi-steel cable, eliminating the need for connectors, reducing the volume and saving space. The use of absorbing materials instead of the traditional epoxy resin glue can not only fix the magnetic ring, but also absorb electromagnetic interference signals, reduce the impact of high-frequency electromagnetic signals on the port, facilitate high-frequency index debugging, and improve high-frequency end technical indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the inner diameter of the magnetic ring and the outer diameter of the coaxial line in the prior art

[0016] Figure 2 This is a schematic diagram of a fixed magnetic ring for absorbing materials in the prior art.

[0017] Figure 3 It is a schematic structural diagram of the improved ultra-wideband board-connected coupler device of the present invention.

[0018] Figure 4 Schematic diagram of the structure of a traditional coupler fixed with epoxy resin glue.

[0019] Figure 5-a Schematic diagram of the standing wave test on the port of the coupler device fixed with epoxy resin glue.

[0020] Figure 5-b Schematic diagram of the standing wave test at the port of the coupler device with the absorbing material fixed.

[0021] Figure 5-c Schematic diagram of the directional test of the coupler device fixed with epoxy resin glue.

[0022] Figure 5-d Schematic diagram of the directivity test of the coupler device fixed with the absorbing material. Description of the drawings:

[0024] 1 RF connector

[0025] 2 Coaxial cable

[0026] 3 Magnetic ring

[0027] 4. Absorbing material block / epoxy resin glue

[0028] 5 Coupler circuit board

[0029] 6 RF source circuit board

[0030] 7 Cavity DETAILED DESCRIPTION

[0031] In order to more clearly describe the technical content of the present invention, further description is given below in conjunction with specific embodiments.

[0032] The improved ultra-wideband board-connected coupler device of the present invention comprises a radio frequency connector 1, a coaxial cable 2, a plurality of magnetic rings 3, an absorbing material 4, a coupler circuit board 5, a radio frequency source circuit board 6 and a cavity 7.

[0033] The coupler circuit board 5 and the RF source circuit board 6 are fixedly mounted on the cavity 7 by screws, the several magnetic rings 3 are fixedly sleeved on the coaxial cable 2, one end of the coaxial cable 2 is connected to the RF source circuit board 6 as the RF signal input end, and the other end is connected to the coupler circuit 5. The device fixes the magnetic ring 3 on the coaxial cable 2 through the absorbing material 4, and the adhesive side of the absorbing material is pasted on the PCB circuit board. The inner conductor of the coaxial cable 2 transmits the signal, and the outer shell is respectively welded to the metal ground of the coupler circuit board 5 and the RF source circuit board 6 to form a common ground.

[0034] As a preferred embodiment of the present invention, the position of the magnetic ring 3 corresponding to the cavity 7 is a hollow structure.

[0035] As a preferred embodiment of the present invention, the outer diameter R2 of the coaxial cable 2 matches the inner diameter R1 of the magnetic ring 3 , that is, the outer diameter R2 of the coaxial cable 2 is as close as possible to the inner diameter R1 of the magnetic ring 3 .

[0036] As a preferred embodiment of the present invention, the absorbing material 4 is used to absorb electromagnetic interference signals, improve the module RF front-end standing wave and directivity indicators, and improve the performance of the entire device.

[0037] As a preferred embodiment of the present invention, the absorbing material 4 can be a rectangular module, a square module, a triangular module, a circular module, an elliptical module, a polygonal module or an irregular module, or other shapes.

[0038] As a preferred embodiment of the present invention, the coupler circuit board 5 includes three microstrip branch lines for debugging the port standing wave and directivity to improve the high-frequency index of the port.

[0039] In a specific embodiment of the present invention, a simple and high-performance board-mounted coupler device is provided, which directly connects the coupler module and the source signal circuit board together in close proximity, improves the fixing method of the coupler magnetic ring, achieves the characteristics of small size, high performance, low cost, and easy production, and can meet the requirements of miniaturization and high performance of current communication test instruments.

[0040] The implementation method of the present invention is to prepare a coupler circuit board, a coaxial cable, several magnetic rings, several absorbing materials, a radio frequency source circuit board and a cavity. The source signal circuit board and the coupler circuit board are fixed on the cavity, the magnetic ring is sleeved on the coaxial cable, and then the inner conductor of the coaxial cable with the magnetic ring is connected to the radio frequency source circuit board at one end as the radio frequency signal input end, and the other end is connected to the coupler circuit, and the magnetic ring is fixed with the absorbing material. The coaxial cable is a semi-steel coaxial cable, and its outer shell is respectively welded to the metal ground of the coupler circuit board and the source signal circuit board to form a common ground.

[0041] The present invention requires that the inner diameter of the opening of the magnetic ring be as small as possible while being able to pass through the coaxial cable, and requires that the coaxial line outer diameter R2 be as close to the inner diameter R1 of the magnetic ring as possible. Even in this case, the magnetic ring will shake if it is not fixed. The present invention uses absorbing materials instead of epoxy resin glue to fix the magnetic ring. One side of the absorbing material is self-adhesive and can be pasted on the PCB circuit board. Two pieces of absorbing materials are placed close to the magnetic ring on both sides of the magnetic ring, and the two pieces of absorbing materials clamp the main magnetic ring and then fix the magnetic ring.

[0042] The coupler device of the embodiment of the present invention is combined with the attached Figure 1 , including a cavity 7, a coupler circuit board 5 and a radio frequency source circuit board 6 are mounted on the cavity 7 and fixed with screws. The radio frequency source circuit board 6 and the coupler circuit board 5 are connected via a coaxial cable 2, the inner conductor of the coaxial cable 2 transmits signals, and the outer shell is grounded.

[0043] A magnetic ring 3 is strung on the coaxial cable 2, and the position of the magnetic ring 3 corresponding to the cavity 7 is a hollow structure. In order to prevent the magnetic ring 3 from shaking, absorbing material blocks 4 are attached to both ends of the magnetic ring 3. The absorbing material blocks 4 are tightly attached to the magnetic ring 3, clamping the magnetic ring 3 to fix the magnetic ring 3. The outer diameter of the coaxial cable 2 used in this embodiment is 1.2 mm, and the inner diameter of the magnetic ring 3 used in this embodiment is 1.3 mm.

[0044] During use, the absorbing material block 4 not only fixes the magnetic ring 3, but also absorbs electromagnetic interference signals, improves the module's RF front-end standing wave and directivity indicators, and improves the performance of the entire device.

[0045] The absorbing material block 4 is a rectangular module, which is only a preferred form of the coupler device of the present invention. It can also have several other shapes, which all belong to the protection scope of the present invention as long as they do not deviate from the concept of the present invention.

[0046] Adding three microstrip branch lines to the coupler circuit board 5 to debug the port standing wave and directivity, combined with the application of absorbing material 4, can greatly improve the high-frequency indicators of the port, achieving a port return loss of less than -15dB and a port directivity greater than 22 in an ultra-wide frequency band of 1MHz to 6GHz.

[0047] Combined with Figure 3 Based on the board-mounted coupler device of the present invention, the port directivity and standing wave index at high frequencies can be significantly improved, thereby improving the overall performance. The specific index comparison is as follows:

[0048] Attached Figure 5-a : The return loss index of the coupler device port fixed with epoxy resin glue, the high frequency band difference, is -10.465dB at 6GHz;

[0049] Attached Figure 5-b : The return loss index of the port of the coupler device with the absorber fixed has improved in the high frequency band, which is -15.705dB at 6GHz;

[0050] Attached Figure 5-c : The directional index of the coupler device fixed with epoxy resin glue is generally poor, with a maximum value of -16.712;

[0051] Attached Figure 5-d: The directivity index of the coupler device with the absorbing material fixed is improved overall, with a maximum of -22.390.

[0052] The improved ultra-wideband board-connected coupler device of the present invention is used to directly connect the coupler circuit board and the radio frequency source circuit board through a semi-steel cable, eliminating the need for connectors, reducing the volume and saving space. The use of absorbing materials instead of the traditional epoxy resin glue can not only fix the magnetic ring, but also absorb electromagnetic interference signals, reduce the impact of high-frequency electromagnetic signals on the port, facilitate high-frequency index debugging, and improve high-frequency end technical indicators.

[0053] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it is apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.

Claims

1. An improved ultra-wideband board-mounted coupler device, characterized in that: The device comprises a radio frequency connector (1), a coaxial cable (2), a plurality of magnetic rings (3), an absorbing material (4), a coupler circuit board (5), a radio frequency source circuit board (6) and a cavity (7); the coupler circuit board (5) and the radio frequency source circuit board (6) are fixedly mounted on the cavity (7) by screws; the plurality of magnetic rings (3) are fixedly sleeved on the coaxial cable (2); one end of the coaxial cable (2) is connected to the radio frequency source circuit board (6) as a radio frequency signal input end, and the other end is connected to the coupler circuit board (5); the device fixes the magnetic ring (3) on the coaxial cable (2) by means of the absorbing material (4); the absorbing material has an adhesive side which is pasted on a PCB circuit board; two pieces of absorbing material are placed close to the magnetic ring on both sides of the magnetic ring; the two pieces of absorbing material clamp the magnetic ring and thereby fix the magnetic ring; the inner conductor of the coaxial cable (2) transmits signals; the outer shell is respectively welded to the metal ground of the coupler circuit board (5) and the radio frequency source circuit board (6) to form a common ground; The wave absorbing material (4) is used to absorb electromagnetic interference signals, improve the standing wave and directivity index of the module radio frequency front end, and improve the performance of the whole device.

2. The improved ultra-wideband board-mounted coupler device according to claim 1, characterized in that: The position of the magnetic ring (3) corresponding to the cavity (7) is a hollow structure.

3. The improved ultra-wideband board-mounted coupler device according to claim 1, characterized in that: The outer diameter R2 of the coaxial cable (2) matches the inner diameter R1 of the magnetic ring (3).

4. The improved ultra-wideband board-mounted coupler device according to claim 1, characterized in that: The wave absorbing material (4) is a rectangular module, a square module, a triangular module, a circular module, an elliptical module or an irregular module.

5. The improved ultra-wideband board-mounted coupler device according to claim 1, characterized in that: The coupler circuit board (5) comprises three microstrip branch lines, which are used for debugging the port standing wave and directivity, and improving the high-frequency index of the port.

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