High-voltage-free frequency hopping filter and manufacturing method thereof

Abstract

The invention discloses a high-voltage-free frequency hopping filter and a manufacturing method thereof, and belongs to the technical field of frequency hopping filters, the high-voltage-free frequency hopping filter comprises a PCB, a 108-225 MHz channel frequency hopping filter and a 225-512 MHz channel frequency hopping filter are arranged on the PCB, the 108-225 MHz channel frequency hopping filter and the 225-512 MHz channel frequency hopping filter are both connected with a GaN chip switch, and the GaN chip switch is connected with a GaN chip. The GaN chip switch is used for driving the frequency hopping filters, and the input ends and the output ends of the 108-225 MHz channel frequency hopping filter and the 225-512 MHz channel frequency hopping filter are connected to the input radio frequency switch and the output radio frequency switch respectively. The GaN chip is used as a switch to drive the frequency hopping filter, so that the power consumption can be reduced, the product size is miniaturized, and the power capacitance value is greatly improved.

Description

Technical Field

[0001] This invention relates to a high-voltage-free frequency hopping filter and its manufacturing method, belonging to the field of frequency hopping filter technology. Background Technology

[0002] like Figure 7-8 The frequency hopping filter shown includes a housing, a coil encapsulated within the housing, and pins located at the bottom of the housing. The pin definitions are shown in the table below.

[0003] Table 1. Pin Definitions of Frequency Hopping Filter Existing conventional frequency hopping filters still require an external high voltage for circuit driving, which will increase the power consumption of the product during operation and will not meet the technical requirements of having an insertion loss of less than or equal to 5dB, a suppression of ±10% of any center frequency from 108MHz to 512MHz greater than or equal to 40dBc, a far-end suppression of greater than or equal to 40dB at twice the center frequency, and a 1dB bandwidth of greater than 5.6MHz.

[0004] Industry research indicates that current frequency hopping filter products have the following problems: 1) Common filters still require an external high voltage for circuit driving, which increases power consumption; 2) The product has too many components due to the driving circuit, making it impossible to break through the performance limits for products of the same size; 3) Power capacity limit. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a high-voltage-free frequency hopping filter and its manufacturing method, which can achieve reduced power consumption, miniaturized product size and significantly increased power capacity.

[0006] To solve the above-mentioned technical problems of the present invention, the technical solution adopted by the present invention is as follows: A high-voltage-free frequency hopping filter, comprising a PCB circuit board, on which a 108-225MHz channel frequency hopping filter and a 225-512MHz channel frequency hopping filter are arranged. Both the 108-225MHz channel frequency hopping filter and the 225-512MHz channel frequency hopping filter are connected to GaN chip switches. The GaN chip switches are used to drive the frequency hopping filter circuit control. The input terminals and output terminals of the 108-225MHz channel frequency hopping filter and the 225-512MHz channel frequency hopping filter are respectively connected to an input RF switch and an output RF switch.

[0007] Furthermore, the aforementioned PCB circuit board has four layers. The first layer houses the components of the frequency hopping filter, while the second, third, and fourth layers house the network connection lines of the frequency hopping filter and the stripline with a 50-ohm impedance. The layout of the frequency hopping filter in each segment of the PCB circuit board is symmetrical.

[0008] Furthermore, the aforementioned frequency hopping filter circuit includes a 108-225MHz channel frequency hopping filter circuit and a 225-512MHz channel frequency hopping filter circuit. Both the 108-225MHz and 225-512MHz channel frequency hopping filter circuits include inductors L1 and L2, which are connected in series and grounded at this connection point. The other end of inductor L1 is connected to one end of inductors L3 and L5. The other end of inductor L3 is connected to the input terminal, and the other end of inductor L5 is connected to the GaN chip switch U1. One end of GaN chip switch U1 is connected to capacitors C1 and C2 and C3 and C4 respectively. The other ends of capacitors C1, C2, C3 and C4 are grounded. The other end of inductor L2 is connected to one end of inductor L4 and inductor L6. The other end of inductor L4 is connected to the output terminal. The other end of inductor L6 is connected to one end of GaN chip switch U2. The other ends of GaN chip switch U2 are connected to capacitors C5 and C6 and C7 and C8 respectively. The other ends of capacitors C5, C6, C7 and C8 are grounded.

[0009] Furthermore, the aforementioned inductors L4, L1, L2, and L3 are obtained by soldering the enameled wire of a single hollow coil to different positions on the pads.

[0010] A method for manufacturing a high-voltage-free frequency hopping filter, the method comprising the following steps: Step 1: Divide the 108MHz-512MHz frequency hopping filter into two filter segments with frequencies of 108MHz-225MHz and 225MHz-512MHz, and two RF switches; Step 2, PCB layout: The PCB has four layers. The first layer contains the frequency hopping filter components and GaN chip. The second, third and fourth layers contain network connection lines and 50-ohm impedance striplines. The frequency hopping filter components are arranged symmetrically in each PCB section. Step 3, the manufacturing steps are as follows: Step 3.1) After preparing the surface mount capacitors and GaN chips for the frequency hopping filter, mount them onto the PCB board according to the circuit diagram of the frequency hopping filter. Align the surface mount capacitors and GaN chips according to their package positions on the PCB board. Use leaded solder paste Sn40Pb60 for SMT machine mounting and reflow soldering to obtain the surface mount semi-finished product. Step 3.2) Prepare the corresponding inductors according to the requirements of the 108-225MHz channel frequency hopping filter and the 512-512MHz channel frequency hopping filter; In the 108-225MHz channel frequency hopping filter: Magnetic ring name: main magnetic ring, magnetic ring specifications: T25-0 magnetic core, copper wire diameter: 0.36mm, number of turns: 13, tap position: 2, quantity: 2, winding direction: counterclockwise; Input / output channels: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 15, quantity 2, winding direction counterclockwise; The lengths of the IN / OUT magnetic ring leads of the frequency hopping filter are: IN: 6mm, 17mm; OUT: 6mm, 17mm, with a tolerance of ±0.1mm. 512-512MHz channel: Magnetic ring name: main magnetic ring, magnetic ring specifications: 2.8mm winding bar, copper wire diameter: 0.45mm, number of turns: 7, tap positions: 2, quantity: 1, winding direction: counterclockwise; Input / output channels: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 2, quantity 2, winding direction counterclockwise; The lengths of the IN / OUT magnetic ring leads of the frequency hopping filter are: IN: 4mm, 16mm; OUT: 4mm, 16mm, with a tolerance of ±0.1mm. Step 3.3) Using leaded solder wire Sn40 / Pb60, 0.5mm, solder all the inductors from Step 3.2) to the corresponding positions on the PCB board according to the pad diagram; Step 3.4) Assemble the semi-finished product assembled in Step 3.3) onto the test fixture, adjust the filter inductor to achieve the set performance index of optimal performance, and then fix it with Nanda 704 silicone. Step 3.5) Seal the metal casing with lead-tin wire Sn40 / Pb60, 0.5mm.

[0011] The beneficial effects of the present invention are as follows: Compared with the prior art, the present invention has the following advantages: 1) By replacing the conventional filter drive circuit with a GaN switch chip, the filter size is reduced to 38.1×25.4×9.8 (±0.2) mm, compared to the conventional size of 54*32*15 mm. Conventional small hop rate filters cannot meet the following requirements at the same size: insertion loss less than or equal to 5dB in the 108MHz~512MHz range, 1dB relative bandwidth greater than or equal to 5.6MHz in the 108MHz~512MHz range, 3dB relative bandwidth greater than or equal to 8MHz in the 108MHz~512MHz range, while maintaining ±10% suppression greater than or equal to 25dBc at any center frequency in the 108MHz~512MHz range, and far-end suppression greater than or equal to 40dB at twice the center frequency. 2) Use enameled wire to make air-core coils to replace conventional inductors. The Q value can reach 250~300 and is adjustable. While ensuring the insertion loss of the filter, it also improves the relative bandwidth by 1dB, the relative bandwidth by 3dB, the center frequency ±10%, and the suppression of the far-end double harmonic. 3) By using GaN switching chips, the conventional high-voltage PIN diode driving circuit is eliminated, so that the filter does not need an external high-voltage power supply. Compared with traditional filters, the overall power consumption is reduced and the power capacity is greatly improved. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the first layer layout of a PCB circuit board; Figure 2 This is a schematic diagram of the second layer layout of a PCB circuit board; Figure 3 This is a schematic diagram of the third layer layout of a PCB circuit board; Figure 4 This is a schematic diagram of the fourth layer layout of a PCB circuit board; Figure 5 This is a schematic diagram of the circuit principle of a GaN chip-based high-voltage-free filter. Figure 6 This is a schematic diagram of the circuit structure of a GaN chip high-voltage-free filter. Figure 7 This is a schematic diagram of the structure of a frequency hopping filter viewed from below; Figure 8 This is a side view of the structure of a frequency hopping filter. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] Invention Concept: By replacing the conventional filter driver circuit with a GaN chip, the filter size is reduced to 38.1×25.4×9.8 (±0.2) mm, compared to the conventional size of 54*32*15 mm. Conventional low-hop-rate filters, at the same size, cannot meet the requirements of insertion loss less than or equal to 5dB in the 108MHz~512MHz range, and a 1dB relative bandwidth greater than or equal to 5.6MHz in the 108MHz~512MHz range. When the 3dB relative bandwidth is greater than or equal to 8MHz, the suppression of ±10% of any center frequency from 108MHz to 512MHz is greater than or equal to 25dBc, and the far-end suppression at twice the center frequency is greater than or equal to 40dB. The main magnetic ring inductor of the filter in this invention uses an air-core coil wound with enameled wire. The air-core coil made with enameled wire replaces the conventional inductor, and the Q value can reach 250~300. It is also adjustable. While ensuring the insertion loss of the filter, it improves the 1dB relative bandwidth, 3dB relative bandwidth, suppression of ±10% of the center frequency and the far-end double harmonic suppression. By using GaN switching chips to replace the conventional high-voltage PIN diode drive circuit, and changing the overall capacitance value of capacitors C1, C2, C3, C4, C5, C6, C7, and C8 connected to the filter, the capacitance value can be changed. This eliminates the need for an external high-voltage power supply to the filter, resulting in reduced overall power consumption and a significant increase in power capacitance compared to traditional filters.

[0015] Example 1: As Figure 1-8 As shown, a high-voltage-free frequency hopping filter includes a PCB circuit board. A 108-225MHz channel frequency hopping filter and a 225-512MHz channel frequency hopping filter are arranged on the PCB circuit board. Both the 108-225MHz and 225-512MHz channel frequency hopping filters are connected to GaN chip switches. The GaN chip switches are used to drive the frequency hopping filters. The input and output terminals of the 108-225MHz and 225-512MHz channel frequency hopping filters are connected to an input RF switch and an output RF switch, respectively. The PCB circuit board is encapsulated in a metal casing, encapsulating the components inside the metal casing.

[0016] The PCB circuit board has four layers. The first layer contains the components of the frequency hopping filter. The second, third, and fourth layers contain the network connection lines of the frequency hopping filter and the stripline with a 50-ohm impedance. The frequency hopping filter is arranged symmetrically on each section of the PCB circuit board.

[0017] The frequency hopping filter circuit includes a 108-225MHz channel frequency hopping filter circuit and a 225-512MHz channel frequency hopping filter circuit. Both circuits include inductors L1 and L2, which are connected in series and grounded at this connection point. The other end of inductor L1 is connected to one end of inductors L3 and L5. The other end of inductor L3 is connected to the input terminal, and the other end of inductor L5 is connected to one end of the GaN chip switch U1. The other two ends of GaN chip switch U1 are connected to capacitors C1 and C2 and C3 and C4 respectively. The other ends of capacitors C1, C2, C3 and C4 are grounded. The other end of inductor L2 is connected to one end of inductors L4 and L6. The other end of inductor L4 is connected to the output terminal. The other end of inductor L6 is connected to one end of GaN chip switch U2. The other two ends of GaN chip switch U2 are connected to capacitors C5 and C6 and C7 and C8 respectively. The other ends of capacitors C5, C6, C7 and C8 are grounded.

[0018] The frequency hopping filter consists of two parts: capacitors, inductors, and GaN chip switches. When the inductance remains constant, the overall capacitance value of capacitors C1, C2, C3, C4, C5, C6, C7, and C8 connected to the filter is changed by switching the GaN chip switches. This achieves the change of capacitance value because the GaN chip does not require high voltage drive, thereby changing the resonant frequency and achieving the purpose of frequency conversion and high voltage elimination.

[0019] Furthermore, the aforementioned inductors L4, L1, L2, and L3 are obtained by soldering the enameled wire of a single hollow coil to different positions on the pads.

[0020] The advantages of this invention are as follows: 1) By replacing the conventional filter drive circuit with a GaN switch chip, the filter size is reduced to 38.1×25.4×9.8 (±0.2) mm, compared to the conventional size of 54*32*15 mm. Conventional small hop rate filters cannot meet the following requirements at the same size: insertion loss less than or equal to 5dB in the 108MHz~512MHz range, 1dB relative bandwidth greater than or equal to 5.6MHz in the 108MHz~512MHz range, 3dB relative bandwidth greater than or equal to 8MHz in the 108MHz~512MHz range, while maintaining ±10% suppression greater than or equal to 25dBc at any center frequency in the 108MHz~512MHz range, and far-end suppression greater than or equal to 40dB at twice the center frequency. 2) Use enameled wire to make air-core coils to replace conventional inductors. The Q value can reach 250~300 and is adjustable. While ensuring the insertion loss of the filter, it also improves the relative bandwidth by 1dB, the relative bandwidth by 3dB, the center frequency ±10%, and the suppression of the far-end double harmonic. 3) By using GaN switching chips, the conventional high-voltage PIN diode driving circuit is eliminated, so that the filter does not need an external high-voltage power supply. Compared with traditional filters, the overall power consumption is reduced and the power capacity is greatly improved.

[0021] Example 2: A method for manufacturing a high-voltage-free frequency hopping filter, the method comprising the following steps: Step 1: Divide the 108MHz-512MHz frequency hopping filter into two filter segments with frequencies of 108MHz-225MHz and 225MHz-512MHz, and two RF switches; Table 2 Circuit Performance Parameters Step 2, PCB layout: The PCB has four layers. The first layer contains the frequency hopping filter components and GaN chip. The second, third and fourth layers contain network connection lines and 50-ohm impedance striplines. The frequency hopping filter components are arranged symmetrically in each PCB section. Step 3, the manufacturing steps are as follows: Step 3.1) After preparing the surface mount capacitors and GaN chips for the frequency hopping filter, mount them onto the PCB board according to the circuit diagram of the frequency hopping filter. Align the surface mount capacitors and GaN chips according to their package positions on the PCB board. Use leaded solder paste Sn40Pb60 for SMT machine mounting and reflow soldering to obtain the surface mount semi-finished product. Step 3.2) Prepare the corresponding inductors according to the requirements of the 108-225MHz channel frequency hopping filter and the 512-512MHz channel frequency hopping filter; In the 108-225MHz channel frequency hopping filter: Magnetic ring name: main magnetic ring, magnetic ring specifications: T25-0 magnetic core, copper wire diameter: 0.36mm, number of turns: 13, tap position: 2, quantity: 2, winding direction: counterclockwise; Input / output channels: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 15, quantity 2, winding direction counterclockwise; The lengths of the IN / OUT magnetic ring leads of the frequency hopping filter are: IN: 6mm, 17mm; OUT: 6mm, 17mm, with a tolerance of ±0.1mm. 512-512MHz channel: Magnetic ring name: main magnetic ring, magnetic ring specifications: 2.8mm winding bar, copper wire diameter: 0.45mm, number of turns: 7, tap positions: 2, quantity: 1, winding direction: counterclockwise; Input / output channels: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 2, quantity 2, winding direction counterclockwise; The lengths of the IN / OUT magnetic ring leads of the frequency hopping filter are: IN: 4mm, 16mm; OUT: 4mm, 16mm, with a tolerance of ±0.1mm. Step 3.3) Using leaded solder wire Sn40 / Pb60, 0.5mm, solder all the inductors from Step 3.2) to the corresponding positions on the PCB board according to the pad diagram; Step 3.4) Assemble the semi-finished product assembled in Step 3.3) onto the test fixture, adjust the filter inductor to achieve the set performance index of optimal performance, and then fix it with Nanda 704 silicone. Step 3.5) Seal the metal casing with lead-tin wire Sn40 / Pb60, 0.5mm. Step 3.6) After sealing, conduct tests and electrical performance index tests to generate a data report. Then, remove the product from the test fixture, clean it, perform external inspection, and package it to form the finished product.

[0022] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

Claims

1. A high-voltage-free frequency hopping filter, characterized by, The PCB circuit board, the GaN chip, the PCB circuit board is provided with 108-225MHz channel frequency hopping filter and 225-512MHz channel frequency hopping filter, the 108-225MHz channel frequency hopping filter and the 225-512MHz channel are all connected with GaN chip switch, the GaN chip switch is used for driving frequency hopping filter circuit control, and the input end and the output end of the 108-225MHz channel frequency hopping filter and the 225-512MHz channel frequency hopping filter are connected to input radio frequency switch and output radio frequency switch respectively.

2. The high-voltage-free frequency hopping filter of claim 1, wherein, The PCB circuit board is provided with four layers, the first layer is placed with the components of the frequency hopping filter, the GaN chip, the second layer, the third layer and the fourth layer are provided with network connection lines and 50-ohm impedance strip lines, and the layout of the frequency hopping filter in each section of the PCB circuit board is symmetrical.

3. The high-voltage-free frequency hopping filter of claim 2, wherein, The circuit of the frequency hopping filter includes 108-225MHz channel frequency hopping filter circuit and 225-512MHz channel frequency hopping filter circuit, the 108-225MHz channel frequency hopping filter circuit and the 225-512MHz channel frequency hopping filter circuit all include inductance L1 and inductance L2, the inductance L1 and the inductance L2 are connected in series, and the series connection is grounded, one end of the inductance L1 is connected to one end of the inductance L3 and the inductance L5, the other end of the inductance L3 is connected to the input end, the other end of the inductance L5 is connected to one end of the GaN chip switch U1, the other two ends of the GaN chip switch U1 are connected to the capacitor C1 and the capacitor C2 and the capacitor C3 and the capacitor C4 respectively, the other ends of the capacitor C1, the capacitor C2, the capacitor C3 and the capacitor C4 are grounded, one end of the inductance L2 is connected to one end of the inductance L4 and the inductance L6, the other end of the inductance L4 is connected to the output end, the other end of the inductance L6 is connected to one end of the GaN chip switch U2, the other two ends of the GaN chip switch U2 are connected to the capacitor C5 and the capacitor C6 and the capacitor C7 and the capacitor C8 respectively, and the other ends of the capacitor C5, the capacitor C6, the capacitor C7 and the capacitor C8 are grounded.

4. The high-voltage-free frequency hopping filter of claim 3, wherein, The inductance L4, the inductance L1, the inductance L2 and the inductance L3 use a lacquered wire of a hollow coil, and four inductances are obtained by welding different positions on the solder pad.

5. The method of claim 2, wherein the high-voltage-free frequency hopping filter is manufactured by the steps of: The method comprises the following steps: ​ Step 1, the frequency hopping filter of 108MHz-512 MHz is divided into two sections of filters of frequencies 108MHz-225MHz and 225MHz-512MHz and two radio frequency switches; Step 2, PCB circuit board layout: the PCB circuit board is provided with four layers, the first layer is placed with the components of the frequency hopping filter and the GaN chip, the second layer, the third layer and the fourth layer are provided with network connection lines and 50-ohm impedance strip lines, and the layout of the frequency hopping filter in each section of the PCB circuit board is symmetrical; Step 3, the manufacturing steps are as follows: Step 3.1) After preparing the patch capacitors of the frequency hopping filter and the GaN chip, patch the frequency hopping filter according to the circuit diagram of the PCB circuit board, and patch the capacitors and GaN chips according to the packaging position on the PCB board. SMT machine is used to patch and reflow soldering with lead-tin paste Sn40Pb60, and a patching semi-finished product is obtained; Step 3.2) According to the requirements of 108-225MHz channel frequency hopping filter and 512-512MHz channel frequency hopping filter, prepare the corresponding inductors; In the 108-225MHz channel frequency hopping filter: the name of the magnetic ring is the main magnetic ring, the magnetic ring specification is T25-0 magnetic core magnetic ring, the copper wire diameter is 0.36mm, the number of turns is 13, the tap position is 2, the number is 2, and the winding direction is counterclockwise; Input / output channel: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 15, number 2, winding direction counterclockwise; The length of the IN / OUT magnetic ring lead of the frequency hopping filter is: IN: 6mm, 17mm; OUT: 6mm, 17mm, tolerance ±0.1mm; 512-512MHz channel: the name of the magnetic ring is the main magnetic ring, the magnetic ring specification is 2.8mm winding rod, the copper wire diameter is 0.45mm, the number of turns is 7, the tap position is 2, the number is 1, and the winding direction is counterclockwise; Input / output channel: magnetic ring specification T16-0, copper wire diameter 0.25mm, number of turns 2, number 2, winding direction counterclockwise; The length of the IN / OUT magnetic ring lead of the frequency hopping filter is: IN: 4mm, 16mm; OUT: 4mm, 16mm, tolerance ±0.1mm; Step 3.3) Use lead-tin wire Sn40 / Pb60, 0.5mm to weld all inductors in step 3.2) to the corresponding position of the PCB circuit board according to the pad diagram; Step 3.4) Assemble the semi-finished product in step 3.3) to the test tool, debug the filter inductor, and reach the optimal performance setting performance index, and then use Nanda 704 silicone to fix; Step 3.5) Seal the metal shell with lead-tin wire Sn40 / Pb60, 0.5mm.

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