30MHz-680MHz high-suppression harmonic filter

Abstract

The utility model discloses a 30MHz-680MHz high-suppression harmonic filter, which comprises a shell, a box cover and a simulation PCB (printed circuit board), a filter circuit and a radio frequency switch circuit are arranged on the simulation PCB, a switch of the radio frequency switch circuit is annularly arranged, the shell is provided with a partition plate to divide the shell into an upper cavity and a lower cavity, the simulation PCB is fixedly connected in the upper cavity, and the box cover is fixedly connected in the lower cavity. The digital PCB is fixedly connected in the lower cavity, the two box covers respectively cover two ends of an upper opening and a lower opening of the shell, the front end of the shell is provided with a connector connected to the digital PCB, the connector serves as a control end of the harmonic filter, and the rear side of the shell is provided with an input end and an output end which are connected to the analog PCB. The annular layout switch is changed to the starting position of each section and the longitudinal layout, and the left and right side layouts are symmetrical, so that the influence of parasitic capacitance is eliminated, the length of the PCB can be greatly reduced, and the total length of the product is greatly reduced.

Description

Technical Field

[0001] The utility model relates to a 30MHz-680MHz high-suppression harmonic filter, belonging to the technical field of harmonic filters. Background Art

[0002] The harmonic filter customized according to customer needs includes a housing, a connector encapsulated on the housing, and a pin identification of the connector. The pin definitions are shown in the following table.

[0003] 1 2 3 4 5 6 +3.3V NC GND GND A0 A1 7 8 9 10 11 12 A2 NC -3.3V NC NC 100V

[0004] This harmonic filter is a customized product, and its package size is the minimum size that can achieve wide bandwidth. The problem when using conventional means to implement harmonic filters is that it cannot meet the miniaturization requirements of customers. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a 30MHz-680MHz high-suppression harmonic filter to solve the problems existing in the above-mentioned prior art.

[0006] The technical scheme adopted by the utility model is: a 30MHz-680MHz high-suppression harmonic filter, comprising a shell, a box cover and an analog PCB board, a filter circuit and a radio frequency switch circuit are arranged on the analog PCB board, the switch of the radio frequency switch circuit is arranged in a ring, a partition is provided on the shell to divide the shell into an upper cavity and a lower cavity, the analog PCB board is fixedly connected in the upper cavity, the digital PCB board is fixedly connected in the lower cavity, two box covers are used, which are respectively covered at both ends of the upper and lower openings of the shell, a connector connected to the digital PCB board is provided at the front end of the shell, the connector serves as a control end of the harmonic filter, and an input end and an output end connected to the analog PCB board are provided at the rear side.

[0007] Furthermore, the box cover is fixed to the outer shell by multiple screws around the periphery, an inwardly convex connecting column is provided on the outer shell at the screw connection, the shapes of the analog PCB board and the digital PCB board are consistent with the cross-section of the inner cavity of the outer shell, the outer shell at the input end and the output end are respectively thickened into flat structures, an inner groove is provided between the two flat structures, the connector is also provided with an inner groove, notches are provided at the four corners of the outer shell, the box cover is a square structure, and the corresponding positions of the notches at the four corners are mounting holes.

[0008] Furthermore, the design of the filter adopts an 11th-order topology structure to achieve broadband communication through segmentation.

[0009] Furthermore, 7-way RF switch gating is arranged on the above-mentioned analog PCB board to turn on or off each section.

[0010] Furthermore, the front and back sides of the upper surface of the above-mentioned analog PCB board are symmetrically arranged, and 30M-680MHz is divided into 7 segments, namely: 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, 512MHz-680MHz.

[0011] Furthermore, the filter circuit and the radio frequency switch circuit are provided in seven groups, and the input side and the output side of the filter circuit of each group are connected to the radio frequency switch circuit.

[0012] Furthermore, the filter circuit includes an inductor L1, an inductor L2, an inductor L3, an inductor L4, an inductor L5, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and a capacitor C13, wherein the inductor L1 is connected in parallel with the capacitor C3, one end of which is connected in parallel to one end of the capacitor C8 and the input end of the filter circuit, and the other end is connected to one end of the capacitor C9 and one end of the inductor L2 and the capacitor C4 connected in parallel, and the other end of the inductor L2 and the capacitor C4 connected in parallel to the input end of the filter circuit. To one end of capacitor C10 and one end of inductor L3 and capacitor C5 in parallel, the other end of inductor L3 and capacitor C5 in parallel is connected to one end of capacitor C11 and one end of inductor L4 and capacitor C6 in parallel, the other end of inductor L4 and capacitor C6 in parallel is connected to one end of capacitor C12 and one end of inductor L5 and capacitor C7 in parallel, the other end of inductor L5 and capacitor C7 in parallel is connected to one end of capacitor C13 and the output end, and the other ends of capacitor C8, capacitor C9, capacitor C10, capacitor C11, capacitor C12 and capacitor C13 are grounded.

[0013] Furthermore, the above-mentioned RF switch circuit includes an input-end RF switch circuit and an output-end RF switch circuit, wherein the input-end RF switch circuit includes a diode D2 and a capacitor C2 connected in series in sequence, the positive electrode of the diode D2 is connected to the input end RF_IN, one end between the connection between the diode D2 and the capacitor C2 is connected to one end of the inductor L7, the other end of the inductor L7 is connected to the capacitor C14 and the resistor R2, the other ends of the capacitor C14 and the resistor R2 are respectively connected to the ground terminal GND and the control terminal k1-2 of the digital PCB board, the other end of the capacitor C2 is connected to the input end of the filter circuit, the inductor L8 and the negative electrode of the diode D4, the other end of the inductor L8 is connected to one end of the capacitor C13 and the resistor R3, the capacitor C13 and the resistor R3 are ... The other end of the resistor R3 is respectively connected to the ground terminal GND and the control terminal k1-1 of the digital PCB board, the anode of the diode D4 is connected to the ground terminal GND, the output end RF switch circuit includes a capacitor C1 and a diode D1 connected in series in sequence, the input end of the capacitor C1 is connected to the output end of the filter circuit and the cathode of the diode D3, the anode of the diode D1 is connected to the output end RFOUT, one end of the capacitor C1 and the diode D1 is connected to one end of the inductor L6, the other end of the inductor L6 is connected to the capacitor C15 and one end of the resistor R1, the anode of the diode D3 and the other end of the capacitor C15 are connected to the ground terminal GND, and the other end of the resistor R1 is connected to the control terminal k1-1 of the digital PCB board.

[0014] Furthermore, after the above seven groups of filter circuits and RF switch circuits are connected in parallel, the two ends are respectively connected to the input circuit and the output circuit, wherein the input circuit includes an inductor L25, one end of the inductor L25 is connected to the input terminal IN and one end of the capacitor C51, the other end of the inductor L25 is connected to one end of the capacitor C52 and the input terminal of the input RF switch circuit, the capacitor C51 and the other end of the capacitor C51 are connected to the ground terminal GND, and the output circuit includes an inductor L31, the two ends of the inductor L31 are respectively connected to the input RF switch circuit and the output terminal OUT.

[0015] Beneficial effects of the utility model: Compared with the prior art, the effects of the utility model are as follows:

[0016] (1) The filter size implemented by the utility model is: length*width*height is 70*55*20 (±0.2mm), such as Figure 4 As shown in the top layout of the analog board, the left and right switches of the analog board are arranged in a ring. The advantage of this is that it can reduce the area of ​​the common pad of the input and output at the switch, thereby reducing the parasitic capacitance generated between segments; by changing the ring layout switch to the beginning of each segment and the vertical layout, and making the layout on the left and right sides symmetrical, the influence of parasitic capacitance can be eliminated, and the PCB length can be greatly reduced, thereby greatly reducing the total length of the product;

[0017] (2) The utility model can realize multi-band switching and achieve a wide frequency band of 30-650MHz. By connecting a parallel resonant circuit in the resonant frequency band of the corresponding section of the filter, a zero point is added in the suppression band, and the harmonic suppression of 2F0~3F0: ≥50dBc, 3F0~4F0: ≥55dBc is achieved at 350MHz~680MHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the top-level layout diagram of the digital board;

[0019] Figure 2 This is the layout diagram of the middle layer of the digital board;

[0020] Figure 3 This is the bottom layout diagram of the digital board;

[0021] Figure 4 This is the top-level layout diagram of the analog board;

[0022] Figure 5 This is the bottom layer layout diagram of the simulation board;

[0023] Figure 6 This is the circuit diagram of the analog board (switch + filter);

[0024] Figure 7 Connect the filter part to the RF part;

[0025] Figure 8 This is the circuit diagram of the 9th order filter model;

[0026] Fig. 9 This is a schematic diagram of the digital board circuit module; U1 is the control chip, the right side is the filter module, and the four drive circuits;

[0027] Fig.10 Power supply module diagram for digital board;

[0028] Fig.11 This is the circuit diagram of 14 groups of digital control switches on the digital board;

[0029] Fig.12 It is a schematic diagram of the three-dimensional structure of the harmonic filter;

[0030] Fig.13 It is a schematic diagram of the harmonic filter structure from a top view;

[0031] Fig.14 for Fig.13 Schematic diagram of the AA section structure;

[0032] Fig.15 for Fig.14 Schematic diagram of the structure of the middle BB section;

[0033] Fig.16 for Fig.14 Schematic diagram of the CC cross-section structure;

[0034] Fig.17 It is the schematic diagram of the rear view structure of the harmonic filter;

[0035] Fig.18 Schematic diagram of the harmonic filter structure with the cover removed. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] Example 1: Figure 1-18 As shown, a 30MHz-680MHz high suppression harmonic filter comprises a shell 1, a box cover 2 and an analog PCB board 3, a filter circuit and a radio frequency switch circuit are arranged on the analog PCB board 3, the switch of the radio frequency switch circuit is arranged in a ring, a partition 15 is provided on the shell 1 to divide the shell 1 into an upper cavity 13 and a lower cavity 14, the analog PCB board 3 is fixedly connected in the upper cavity 13, and the digital PCB board 12 is fixedly connected in the lower cavity 14 through a support column 16, two box covers 2 are used, which are respectively covered at the upper and lower opening ends of the shell 1, and the box cover 2 is covered at one end of the opening of the shell 1, a connector 4 connected to the digital PCB board is provided at the front end of the shell 1, and the connector serves as the control end of the harmonic filter, and an input end 5 and an output end 6 are provided on the rear side, a plurality of threading holes 17 are provided around the partition 15, and a plurality of air holes 18 are provided on the board surface, so as to facilitate wiring and heat dissipation.

[0038] Furthermore, the box cover 2 is fixed to the shell 1 by a plurality of screws 7 around a circle, an inwardly convex connecting column 8 is provided on the shell 1 at the connection of the screws 7, the shapes of the analog PCB board 3 and the digital PCB board 12 are consistent with the cross-section of the inner cavity of the shell 1, the shell 1 at the input end 5 and the output end 6 are respectively thickened into a flat structure, an inner groove 9 is provided between the two flat structures, the connector 4 is also provided with an inner groove, notches 10 are provided at the four corners of the shell 1, the box cover 2 is a square structure, and the corresponding positions of the four corner notches 10 are mounting holes 11.

[0039] Furthermore, the design of the filter adopts an 11th-order topology structure to achieve broadband communication through segmentation.

[0040] Furthermore, 7-way RF switch gating is arranged on the above-mentioned analog PCB board 3 to switch each section on or off.

[0041] Furthermore, the front and rear sides of the upper surface of the above-mentioned analog PCB board 3 are symmetrically arranged, and 30M-680MHz is divided into 7 segments, namely: 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, and 512MHz-680MHz.

[0042] Furthermore, the filter circuit and the radio frequency switch circuit are provided in seven groups, and the input side and the output side of the filter circuit of each group are connected to the radio frequency switch circuit.

[0043] Further, the filter circuit comprises an inductor L1, an inductor L2, an inductor L3, an inductor L4, an inductor L5, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and a capacitor C13, the inductor L1 is connected in parallel with the capacitor C3, one end of the parallel connection is connected to one end of the capacitor C8 and the input end of the filter circuit, and the other end is connected to one end of the capacitor C9 and one end of the inductor L2 and the capacitor C4 in parallel, and the other end of the inductor L2 and the capacitor C4 in parallel is connected to The first embodiment is connected to one end of capacitor C10 and one end of inductor L3 connected in parallel with capacitor C5, the other end of inductor L3 connected in parallel with capacitor C5 is connected to one end of capacitor C11 and one end of inductor L4 connected in parallel with capacitor C6, the other end of inductor L4 connected in parallel with capacitor C6 is connected to one end of the capacitor and one end of inductor L5 connected in parallel with capacitor C7, the other end of inductor L5 connected in parallel with capacitor C7 is connected to one end of capacitor C13 and the output end, and the other ends of capacitor C8, capacitor C9, capacitor C10, capacitor C11, capacitor C12 and capacitor C13 are grounded.

[0044] Furthermore, the above-mentioned RF switch circuit includes an input-end RF switch circuit and an output-end RF switch circuit, wherein the input-end RF switch circuit includes a diode D2 and a capacitor C2 connected in series in sequence, the positive electrode of the diode D2 is connected to the input end RF_IN, one end between the connection between the diode D2 and the capacitor C2 is connected to one end of the inductor L7, the other end of the inductor L7 is connected to the capacitor C14 and the resistor R2, the other ends of the capacitor C14 and the resistor R2 are respectively connected to the ground terminal GND and the control terminal k1-2 of the digital PCB board, the other end of the capacitor C2 is connected to the input end of the filter circuit, the inductor L8 and the negative electrode of the diode D4, the other end of the inductor L8 is connected to one end of the capacitor C13 and the resistor R3, the capacitor C13 and the resistor R3 are ... The other end of the resistor R3 is respectively connected to the ground terminal GND and the control terminal k1-1 of the digital PCB board, the anode of the diode D4 is connected to the ground terminal GND, the output end RF switch circuit includes a capacitor C1 and a diode D1 connected in series in sequence, the input end of the capacitor C1 is connected to the output end of the filter circuit and the cathode of the diode D3, the anode of the diode D1 is connected to the output end RFOUT, one end of the capacitor C1 and the diode D1 is connected to one end of the inductor L6, the other end of the inductor L6 is connected to the capacitor C15 and one end of the resistor R1, the anode of the diode D3 and the other end of the capacitor C15 are connected to the ground terminal GND, and the other end of the resistor R1 is connected to the control terminal k1-1 of the digital PCB board.

[0045] Furthermore, after the above seven groups of filter circuits and RF switch circuits are connected in parallel, the two ends are respectively connected to the input circuit and the output circuit, wherein the input circuit includes an inductor L25, one end of the inductor L25 is connected to the input terminal IN and one end of the capacitor C51, the other end of the inductor L25 is connected to one end of the capacitor C52 and the input terminal of the input RF switch circuit, the capacitor C51 and the other end of the capacitor C51 are connected to the ground terminal GND, and the output circuit includes an inductor L31, the two ends of the inductor L31 are respectively connected to the input RF switch circuit and the output terminal OUT.

[0046] Example 2: Figure 1-18 As shown, a method for manufacturing a 30MHz-680MHz high suppression harmonic filter, the method comprising the following steps:

[0047] Step 1: PCB circuit board layout design: The PCB circuit board is divided into two boards, namely the digital board and the analog board. The digital board adopts a three-layer layout, which is equipped with a drive circuit, 14 sets of CNC switch circuits and a power filter circuit. The analog board adopts a two-layer layout, with a large-area ground at the bottom layer and RF routing at the top layer, which is equipped with RF switch circuits and filter circuits (such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5), a large area of ​​grounding is laid in the space outside the pads and traces of the components of the analog board and the digital board. The layout of the top PCB circuit of the analog board adopts left-right symmetry, 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 later product manufacturing and the filter debugging; the filter is designed in a segmented manner, and a single-pole 7-way RF switch is built using PIN diodes. During debugging, it can be debugged according to the frequency characteristics of each segment, reducing the difficulty of debugging and facilitating control and suppression; the left and right switches of the RF switch circuit are arranged in a ring on the analog PCB board, and the left and right switches of the analog board are arranged in a ring. The advantage of this is that it can reduce the area of ​​the common terminal pad of the input and output at the switch, thereby reducing the parasitic capacitance generated between segments; by changing the ring layout, changing the switch to the starting position of each segment and the longitudinal layout, and making the left and right sides symmetrical, the influence of parasitic capacitance is eliminated, and the length of the PCB can be greatly reduced, thereby greatly reducing the total length of the product.

[0048] Step 2: The manufacturing method is as follows:

[0049] 2.1) Press Figure 3 Digital board bottom layout diagram, Figure 4 Materials required for the top layout diagram of the analog board Prepare the chip electronic materials, patch according to the circuit diagram of the harmonic filter, use lead solder paste Sn40Pb60 for SMT machine patch, reflow soldering, and obtain the patch semi-finished products; the advantages of this process are quantitative distribution of solder paste, high precision, less solder heating times, and less impurities. Reflow soldering can ensure the temperature uniformity in the flow area;

[0050] 2.2) According to the frequency bands of 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, and 512MHz-680MHz, prepare the inductors required for the 7 bands and the corresponding switch parts; the front and back sides of the upper surface of the PCB board are symmetrically arranged, and 30M-680MHz is divided into 7 frequency bands, namely: 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, and 512MHz-680MHz;

[0051] Among them, the five inductance parameters corresponding to 30MHz-50MHz include: 3.0*0.3*8.5T, 2.5*0.3*6.5T, 2.5*0.3*7.5T, 3.5*0.3*8.5T and 2.0*0.3*5.5T;

[0052] The five inductance parameters corresponding to 50MHz-82MHz include: 3.0*0.3*5.5T, 2.5*0.3*4.5T, 2.5*0.3*5.5T, 3.0*0.3*6.5T and 2.0*0.3*4.5T;

[0053] The five inductance parameters corresponding to 82MHz-136MHz include: 2.5*0.3*4.5T, 2.0*0.3*3.5T, 2.0*0.3*4.5T, 2.5*0.3*5.5T and 1.5*0.3*2.5T;

[0054] The five inductance parameters corresponding to 136MHz-225MHz include: 2.0*0.3*4.5T, 1.5*0.3*3.5T, 2.0*0.3*3.5T, 2.0*0.3*4.5T and 1.5*0.3*3.5T;

[0055] The five inductance parameters corresponding to 225MHz-350MHz include: 1.5*0.3*3.5T, 1.5*0.3*2.5T, 2.0*0.3*2.5T, 2.0*0.3*3.5T and 1.0*0.3*3.5T;

[0056] The five inductance parameters corresponding to 350MHz-512MHz include: 1.5*0.3*2.5T, 1*0.3*3.5T, 1.5*0.3*2.5T, 1.5*0.3*3.5T and 1.0*0.3*3.5T;

[0057] The three inductance parameters corresponding to 512MHz-680MHz include: 1.0*0.3*2.5T, 1.5*0.3*2.5T, 1.5*0.3*1.5T;

[0058] The five inductance parameters corresponding to the switch part include: 1.2*0.3*2.5T, 1.2*0.3*1.5T, 2.0*0.4*2.5T, 2.0*0.4*1.5T and 1.2*0.3*2.5T;

[0059] 2.3) Use lead tin wire Sn40 / Pb60, 0.5mm wire to solder the inductor in step 2.2) to the corresponding position of the PCB circuit board according to the pad diagram;

[0060] 2.4) Assemble the semi-finished products (digital board and analog board) together and Fig.14Install the product into the housing as shown in the internal diagram, debug the filter inductance, and if it does not meet the index, increase or decrease the number of inductance turns and debug again until the index performance is achieved. Then use Nanda 704 silicone to fix the debugged inductance to the PCB circuit board and fix each turn of the debugged inductance to prevent it from loosening or deformation due to external environmental factors such as vibration.

[0061] 2.5) After the digital board and analog board are installed, cover the box and screw them in to seal the cover;

[0062] 2.6) After capping, conduct tests and electrical performance index tests, generate data reports, clean, inspect and package the products to form finished products.

[0063] Furthermore, the circuit of the 30MHz-680MHz high suppression filter prepared above adopts an eleventh-order filter design.

[0064] Furthermore, the design of the filter adopts an 11th-order topology structure to achieve broadband communication through segmentation.

[0065] Furthermore, 7-way RF switch gates are arranged on the PCB board 3 to switch each section on or off.

[0066] Furthermore, the front and rear sides of the upper surface of the PCB board 3 are symmetrically arranged, and 30M-680MHz is divided into 7 frequency bands, namely: 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, and 512MHz-680MHz.

[0067] The circuit performance parameters are shown in Table 2:

[0068] Table 2 Circuit performance parameters

[0069]

[0070] 30MHz-680MHz high suppression harmonic filter circuit such as Figure 7 As shown, conventional 30MHz-680MHz harmonic filters cannot meet the harmonic suppression requirements of 2F0~3F0: ≥50dBc, 3F0~4F0: ≥55dBc at 350MHz~680MHz;

[0071] The circuit in the utility model divides 30MHz-680MHz into 7 segments, and uses PIN diodes to build a single-pole 7-throw RF switch (such as Figure 6 ), while ensuring the filter performance, maintaining low insertion loss and high harmonic suppression.

[0072] The circuit structure is divided into two major boards, namely the digital board and the analog board. The digital board is composed of the digital board. Through the external control signal, the digital board can output a -3.3v control signal and a +100v high-voltage signal to the analog board; the analog board is composed of the analog board, which is mainly divided into a filter part and a switch part. The -3.3v control signal output by the digital board can control the conduction of the switch part on the analog board, thereby making the filter part of the corresponding segment conduct and work. At the same time, the +100v high voltage will also be passed into the conducted filter part to meet the power requirements.

[0073] Compared with the single frequency band of ordinary passive LC filters, this circuit structure can realize multi-band switching of filter frequencies and meet higher power requirements.

[0074] The product is installed as a whole in a metal shell, and the metal cover is fastened by screws; this structure has a compact appearance and high strength, and it is not easy to cause direct damage to the PCB by separating the PCB from the installation environment. The PCB is easy to disassemble and has high maintainability, good overall shielding effect, and strong anti-interference ability.

[0075] 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 30MHz-680MHz high suppression harmonic filter, characterized in that: The invention comprises a housing (1), a box cover (2), an analog PCB board (3) and a digital PCB board (12); a filter circuit and a radio frequency switch circuit are arranged on the analog PCB board (3); the switches of the radio frequency switch circuit are arranged in a ring; a partition (15) is provided on the housing (1) to divide the housing (1) into an upper cavity (13) and a lower cavity (14); the analog PCB board (3) is fixedly connected in the upper cavity (13); the digital PCB board (12) is fixedly connected in the lower cavity (14); two box covers (2) are used, which cover the upper and lower openings of the housing (1) respectively; a connector (4) connected to the digital PCB board (12) is provided at the front end of the housing (1); and an input end (5) and an output end (6) connected to the analog PCB board (3) are provided at the rear side.

2. A 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: The box cover (2) is fixed to the housing (1) by a plurality of screws (7) around the box cover. The housing (1) is provided with an inwardly convex connection column (8) at the connection of the screws (7). The shapes of the analog PCB board (3) and the digital PCB board (12) are consistent with the cross-section of the inner cavity of the housing (1). The housing (1) at the input end (5) and the output end (6) are respectively thickened into a flat structure. An inner groove (9) is provided between the two flat structures. The connector (4) is also provided with an inner groove. Notches (10) are provided at the four corners of the housing (1). The box cover (2) is a square structure. The corresponding positions of the four corner notches (10) are mounting holes (11).

3. A 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: The filter design uses an 11th-order topology to achieve broadband communication through segmentation.

4. A 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: Seven radio frequency switch gates are arranged on the analog PCB board (3) to switch each section on or off.

5. The 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: The front and rear sides of the upper surface of the analog PCB board (3) are symmetrically arranged, and 30M-680MHz is divided into 7 sections, namely: 30MHz-50MHz, 50MHz-82MHz, 82MHz-136MHz, 136MHz-225MHz, 225MHz-350MHz, 350MHz-512MHz, and 512MHz-680MHz.

6. A 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: The filter circuit and the radio frequency switch circuit are in seven groups, and the input side and the output side of the filter circuit of each group are connected with the radio frequency switch circuit.

7. A 30MHz-680MHz high suppression harmonic filter according to claim 6, characterized in that: The filter circuit includes an inductor L1, an inductor L2, an inductor L3, an inductor L4, an inductor L5, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and a capacitor C13. The inductor L1 is connected in parallel with the capacitor C3, one end of which is connected in parallel to one end of the capacitor C8 and the input end of the filter circuit, and the other end is connected to one end of the capacitor C9 and one end of the inductor L2 and the capacitor C4 in parallel, and the other end of the inductor L2 and the capacitor C4 in parallel to the capacitor C One end of the inductor L10 is connected to one end of the inductor L3 and the capacitor C5 in parallel, the other end of the inductor L3 and the capacitor C5 in parallel is connected to one end of the capacitor C11 and one end of the inductor L4 and the capacitor C6 in parallel, the other end of the inductor L4 and the capacitor C6 in parallel is connected to one end of the capacitor C12 and one end of the inductor L5 and the capacitor C7 in parallel, the other end of the inductor L5 and the capacitor C7 in parallel is connected to one end of the capacitor C13 and the output end, and the other ends of the capacitors C8, C9, C10, C11, C12 and C13 are grounded.

8. A 30MHz-680MHz high suppression harmonic filter according to claim 7, characterized in that: The RF switch circuit includes an input RF switch circuit and an output RF switch circuit, wherein the input RF switch circuit includes a diode D2 and a capacitor C2 connected in series in sequence, the positive electrode of the diode D2 is connected to the input terminal RF_IN, one end between the connection between the diode D2 and the capacitor C2 is connected to one end of the inductor L7, the other end of the inductor L7 is connected to the capacitor C14 and the resistor R2, the other ends of the capacitor C14 and the resistor R2 are respectively connected to the ground terminal GND and the control terminal k1-2 of the digital PCB board, the other end of the capacitor C2 is connected to the input end of the filter circuit, the inductor L8 and the negative electrode of the diode D4, the other end of the inductor L8 is connected to one end of the capacitor C13 and the resistor R3, the The other end is respectively connected to the ground terminal GND and the control terminal k1-1 of the digital PCB board, the anode of the diode D4 is connected to the ground terminal GND, the output end RF switch circuit includes a capacitor C1 and a diode D1 connected in series, the input end of the capacitor C1 is connected to the output end of the filter circuit and the cathode of the diode D3, the anode of the diode D1 is connected to the output end RFOUT, one end between the capacitor C1 and the diode D1 is connected to one end of the inductor L6, the other end of the inductor L6 is connected to the capacitor C15 and one end of the resistor R1, the anode of the diode D3 and the other end of the capacitor C15 are connected to the ground terminal GND, and the other end of the resistor R1 is connected to the control terminal k1-1 of the digital PCB board.

9. The 30MHz-680MHz high suppression harmonic filter according to claim 1, characterized in that: After the seven groups of filter circuits and the RF switch circuit are connected in parallel, the two ends are respectively connected to the input circuit and the output circuit, wherein the input circuit includes an inductor L25, one end of the inductor L25 is connected to the input terminal IN and one end of the capacitor C51, the other end of the inductor L25 is connected to one end of the capacitor C52 and the input end of the input RF switch circuit, the capacitor C51 and the other end of the capacitor C51 are connected to the ground terminal GND, and the output circuit includes an inductor L31, the two ends of the inductor L31 are respectively connected to the input RF switch circuit and the output terminal OUT.

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