10MHz-600MHz high-performance small-size coupler

Abstract

The utility model discloses a 10MHz-600MHz high-performance small-size coupler, which comprises a PCB (printed circuit board) and a double-hole magnetic core, the PCB is provided with two layers, each layer of the PCB is grounded in a large area, the ground is paved in the space outside element pads and wires on the PCB, the bottom layer of the PCB is complete ground, inductors arranged on the PCB are arranged in a bilateral symmetry manner, and the double-hole magnetic core is arranged on the PCB. The double-hole magnetic core is formed by winding an inductor L1, an inductor L2, an inductor L3 and an inductor L4 through enameled wires, and leads of the inductor L1, the inductor L2, the inductor L3 and the inductor L4 are welded to corresponding bonding pads of the PCB and fixed to the PCB through epoxy resin after being wound. The product prepared by the utility model is small in size and adjustable, and the index of the directional coupler can be optimized.

Description

Technical Field

[0001] The utility model relates to a 10MHz-600MHz high-performance small-size coupler, belonging to the technical field of directional couplers. Background Art

[0002] In modern communication and microwave systems, directional couplers have extremely wide applications and are an important part of microwave circuits. Directional couplers are passive devices that can be designed with any power distribution ratio and are widely used in power detection, power distribution and power synthesis, such as transmitter power control and standing wave protection. In particular, with the development of modern communication and microwave system miniaturization, the performance requirements for directional couplers are becoming higher and higher, and the development is moving towards small size, wide bandwidth, high power, high directivity and other directions.

[0003] like Figure 3-5 As shown, it includes a coil soldered on a PCB board and pins arranged at the bottom of the housing. The pin definitions are shown in the following table.

[0004] Serial number 1 2 3 4 5 6 definition Coupling (Isolation) land Input(Output) Output(Input) / Isolation (coupling)

[0005] Existing directional couplers of the same size cannot meet the requirement that the insertion loss is less than or equal to 1.3 dB, while the coupling degree at any frequency of 10 MHz to 600 MHz is between 10.2 and 11.8 dB, and the directivity is greater than or equal to 10 dB. Summary of the invention

[0006] The technical problem to be solved by the utility model is to provide a 10MHz-600MHz high-performance small-size coupler to solve the problems existing in the above-mentioned prior art.

[0007] The technical scheme adopted by the utility model is: a 10MHz-600MHz high-performance small-size coupler, including a PCB circuit board and a double-hole magnetic core, the PCB circuit board is provided with two layers, each layer of the PCB circuit board is grounded in a large area, the space outside the component pads and the wiring on the PCB circuit board is paved with the ground, the bottom layer of the PCB circuit board is a complete ground, the inductors arranged on the PCB circuit board are arranged symmetrically on the left and right, the double-hole magnetic core adopts enameled wire to wind the inductor L1, the inductor L2, the inductor L3 and the inductor L4, the leads of the inductor L1, the inductor L2, the inductor L3 and the inductor L4 are welded on the corresponding pads of the PCB circuit board, and are fixed on the PCB circuit board with epoxy resin after winding.

[0008] Furthermore, the circuit of the above-mentioned coupler includes inductor L1, inductor L2, inductor L3 and inductor L4, one end of inductor L1 is connected to the coupling end, and the other end is connected to the isolation end and one end of inductor L3, the other end of inductor L3 is connected to one end of inductor L2 and the ground end, the other end of inductor L2 is connected to one end of inductor L4 and the output end, and the other end of inductor L4 is connected to the input end.

[0009] Furthermore, the copper wire of the inductor L1 Wrap one circle, the copper wire of inductor L2 0.12 winding number of turns six turns, inductor L3 copper wire The number of winding turns is six, the copper wire of inductor L4 0.12 winding turns per circle.

[0010] Beneficial effects of the utility model: Compared with the prior art, the effects of the utility model are as follows:

[0011] 1) The product size is small, 3.81×3.81×4 (tolerance ±0.3mm), mainly by using a double-hole magnetic core to ensure the use of a small magnetic core under the same magnetic inductance, thereby making the entire coupler smaller;

[0012] 2) Use enameled wire wound on an air-core magnetic core. The position (spacing) between the enameled wires on the magnetic core can be adjusted to optimize the directional coupler performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of PCB circuit board welding;

[0014] Figure 2 This is the block diagram of a high performance small size coupler;

[0015] Figure 3 It is a top view structural diagram of a high performance small size coupler;

[0016] Figure 4 It is a left-view structural diagram of a high-performance small-size coupler;

[0017] Figure 5 It is a schematic diagram of the structure of a high-performance small-size coupler viewed from above;

[0018] Figure 6 It is a side view structural diagram of the test tooling;

[0019] Figure 7 It is a front view structural diagram of the test tooling. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Example 1: Figure 1-7 As shown, a 10MHz-600MHz high-performance small-size coupler includes a PCB circuit board and a double-hole magnetic core. The PCB circuit board is provided with two layers. Each layer of the PCB circuit board is grounded over a large area. The space other than the component pads and the routing on the PCB circuit board is paved with the ground. The bottom layer of the PCB circuit board is a complete ground. The inductors arranged on the PCB circuit board are arranged symmetrically on the left and right, so that the parasitic capacitance and inductance generated by the left and right pads are equal, which better meets the impedance matching of the overall product, facilitates the subsequent product manufacturing and the filter debugging, and the double-hole magnetic core adopts enameled wire to wind the inductor L1, the inductor L2, the inductor L3 and the inductor L4. The leads of the inductor L1, the inductor L2, the inductor L3 and the inductor L4 are welded on the corresponding pads of the PCB circuit board, and are fixed on the PCB circuit board with epoxy resin after winding.

[0022] Furthermore, the circuit of the above-mentioned coupler includes inductor L1, inductor L2, inductor L3 and inductor L4, one end of inductor L1 is connected to the coupling end, and the other end is connected to the isolation end and one end of inductor L3, the other end of inductor L3 is connected to one end of inductor L2 and the ground end, the other end of inductor L2 is connected to one end of inductor L4 and the output end, and the other end of inductor L4 is connected to the input end.

[0023] Furthermore, the copper wire of the inductor L1 Wrap one circle, the copper wire of inductor L2 0.12 winding number of turns six turns, inductor L3 copper wire The number of winding turns is six, the copper wire of inductor L4 0.12 winding turns per circle.

[0024] Example 2: Figure 1-7 As shown, a manufacturing method of a 10MHz-600MHz high-performance small-size coupler, the circuit of the coupler includes an inductor L1, an inductor L2, an inductor L3 and an inductor L4, one end of the inductor L1 is connected to the coupling end, and the other end is connected to the isolation end and one end of the inductor L3, the other end of the inductor L3 is connected to one end of the inductor L2 and the ground end, the other end of the inductor L2 is connected to one end of the inductor L4 and the output end, and the other end of the inductor L4 is connected to the input end. The manufacturing method includes the following steps:

[0025] Step 1. PCB circuit board layout: The PCB circuit board is set up with two layers. Each layer of the PCB circuit board is grounded through a large area. The space outside the component pads and traces is paved with the ground. The bottom layer of the PCB board is a complete ground. The PCB circuit board uses a large number of grounding through holes to increase the grounding effect.

[0026] Step 2: The manufacturing method comprises the following steps:

[0027] 2.1) After preparing the PCB circuit board and the magnetic core, use epoxy resin E107-HF to bond according to the bonding diagram of the coupler, and then bake to obtain a semi-finished product;

[0028] 2.2) Prepare the corresponding magnetic core according to the parameter table in Table 1, and wind it on the magnetic core in a clockwise direction;

[0029]

[0030] 2.3) Use an electronic spot welder to spot weld the enameled wire to the corresponding position of the PCB board according to the welding diagram;

[0031] 2.4) Use high temperature tin wire LC_D, 0.8mm to tin at the spot welding position;

[0032] 2.5) After tinning, the product is tested on the test fixture and the electrical performance index is tested to form a data report. Then the product is removed from the test fixture, cleaned, inspected, and packaged to form a finished product. The test parameters are as follows:

[0033] Use test fixtures to test electrical performance indicators. There is no need to weld product pins during debugging and testing, avoiding secondary welding at the customer end.

[0034] 2.5.1 Coupling Test

[0035] Use a network analyzer that meets the requirements for frequency range and resolution to conduct the test. The corresponding test fixture loss should be subtracted from the instrument test, and the following details should be used for the test:

[0036] (a) Test frequency: 10MHz~600MHz;

[0037] (b) Test ports: input port 3, coupling port 6;

[0038] (c) Test environment temperature: 25°C, -40°C, 85°C;

[0039] (d) Other ports should be connected to 50Ω matched load;

[0040] 2.5.2 Directivity test

[0041] Use a network analyzer that meets the requirements for frequency range and resolution to conduct the test, and use the following details for testing:

[0042] (a) Test frequency: 10MHz~600MHz;

[0043] (b) Test ports: input port 3, isolation port 6, coupling port 1;

[0044] (c) Test environment temperature: 25°C, -40°C, 85°C;

[0045] (d) Other ports should be connected to 50Ω matched load;

[0046] 2.5.3 Insertion loss test

[0047] Use a network analyzer that meets the requirements for frequency range and resolution to conduct the test, and use the following details for testing:

[0048] (a) Test frequency: 10MHz~600MHz;

[0049] (b) Test ports: input port 3, output port 4;

[0050] (c) Test environment temperature: 25°C, -40°C, 85°C;

[0051] (d) Other ports should be connected to 50Ω matched load;

[0052] 2.5.4 Standing wave ratio test

[0053] Use a network analyzer that meets the requirements for frequency range and resolution to conduct the test, and use the following details for testing:

[0054] (a) Test frequency: 10MHz~600MHz;

[0055] (b) Test ports: input port 3, output port 4;

[0056] (c) Test environment temperature: 25°C, -40°C, 85°C;

[0057] (d) Other ports should be connected to a 50Ω matched load.

[0058] Table 2 Circuit performance parameters

[0059] Theoretical frequency Measured frequency Insertion loss Coupling Directionality VSWR (MHz) (MHz) ≤1.3 11±0.8 ≥10 ≤1.5 10 10.5 0.98 11.31 10 1.21 350 350.2 1.02 11.52 14 1.13 600 600.1 1.12 11.72 16 1.35

[0060] (When testing 10MHz-600MHz high-performance small-size couplers, the existing conventional technology usually uses direct welding cables to the couplers for testing or direct welding on PCB pads for welding. This method is easy to damage the pads of the couplers, which leads to unreliable pad welding during use. In addition, welding is time-consuming and labor-intensive, and the test efficiency is low.) Figure 6-7As shown, the test fixture includes a pressing arm 1, a PCB substrate 2, a base 3 and a column 4. The PCB substrate 2 is fixedly connected to the upper surface of the base 3. The PCB substrate 2 is provided with an RFin terminal 5, an RFout terminal 6, an isolation / coupling terminal 7 and a coupling / isolation terminal 8. The PCB substrate 2 is provided with a pad for docking the coupler 9 pins. The pressing arm 1 movably passes through a guide frame 10 provided on the front side of the column 4. A compression spring 11 is sleeved on the pressing arm 1. The lower end of the compression spring 11 abuts against a limit pin 12, and the upper end abuts against the inner side of the top of the guide frame 10. The limit pin 12 is connected to the pressing arm 1 through a thread. When the test fixture is used for testing, the coupler is directly placed on the PCB substrate and fixed by pressing with the pressing arm. No additional welding wires or welding on the pads to connect the test equipment are required, so as to avoid the coupler The pad is damaged, which improves the test efficiency and test stability. A plurality of threaded holes 13 for connecting the limit pins 12 are arranged on the pressing arm 1 along its length direction, which can realize the adjustment of different pressures and adapt to the needs of different products and the height requirements of different products. It has a wider range of applications and lower costs. The guide frame 10 is a front-end opening structure, which is formed by four wall panels fixedly connected. A pressing block 14 is arranged at the lower end of the pressing arm 1, and a hard plastic pressing head 15 is arranged at the lower end of the pressing block 14. It can play a protective role when pressing the device to avoid damage to the pressed device under test. A shock-absorbing rubber pad 16 is arranged between the PCB substrate 2 and the base 3, which can play a buffering and protective role. The column 4 is an L-shaped structure, and the fixed connection is more stable and reliable, which is convenient for installation. A through hole 17 is arranged in the middle of the column to facilitate threading on the back side of the PCB board.

[0061] How it works:

[0062] 1. Connect the two RF cables to Figure 6 At the "RFin end" and "RFout end" in the

[0063] 2. Lift the pressing arm of the test fixture, align the input and output ports of the directional coupler to be tested with the corresponding positions of the test fixture, press the product with the test fixture and make the bottom of the directional coupler fit tightly with the ground of the test fixture;

[0064] 3. Connect the "RFin" RF line to the output port of the network analyzer and the "RFout" RF line to the input port of the network analyzer for measurement.

[0065] The above description is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present utility model, which should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims

1. A 10MHz-600MHz high performance small size coupler, characterized by: The invention comprises a PCB circuit board and a double-hole magnetic core. The PCB circuit board is provided with two layers. Each layer of the PCB circuit board is grounded over a large area. The space other than the component pads and the routing on the PCB circuit board is paved with the ground. The bottom layer of the PCB circuit board is a complete ground. The inductors arranged on the PCB circuit board are arranged symmetrically on the left and right. The double-hole magnetic core adopts enameled wire to wind the inductors L1, L2, L3 and L4. The leads of the inductors L1, L2, L3 and L4 are welded on the corresponding pads of the PCB circuit board and are fixed on the PCB circuit board with epoxy resin after winding.

2. A 10MHz-600MHz high performance small size coupler according to claim 1, characterized in that: The circuit of the coupler includes inductor L1, inductor L2, inductor L3 and inductor L4. One end of inductor L1 is connected to the coupling end, and the other end is connected to the isolation end and one end of inductor L3. The other end of inductor L3 is connected to one end of inductor L2 and the ground end. The other end of inductor L2 is connected to one end of inductor L4 and the output end. The other end of inductor L4 is connected to the input end.

3. A 10MHz-600MHz high performance small size coupler according to claim 1, characterized in that: The copper wire φ0.12 of the inductor L1 is wound once, the copper wire φ0.12 of the inductor L2 is wound six times, the copper wire φ0.12 of the inductor L3 is wound six times, and the copper wire φ0.12 of the inductor L4 is wound once.

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