A 6A type high gain amplifier module and its manufacturing method

Abstract

The invention discloses a 6A type high-gain amplifier module and a manufacturing method thereof, wherein the manufacturing method comprises: step 1: preparing a cavity, a circuit board, a pressure strip, and a cover plate, and processing the structural parts; step 2: processing the circuit board of the high-gain amplifier; step 3: cleaning the printed circuit board, removing the dirt layer and air drying; step 4: cleaning the cavity and the cover plate; step 5: welding components to the printed circuit board; step 6: cleaning the circuit board with components adhered, removing the dirt layer and air drying; step 7: welding the lead wire; step 8: installing the circuit board; step 9: assembling the isolator, the power amplifier chip, and the voltage stabilizing chip on the cavity and welding; step 10: assembling the SMA connector, the DB9 connector and the pressure strip; step 11: preliminary debugging of the 6A type high-gain amplifier. Step 12: sealing the cover; placing the cover plate on the cavity and fixing it with screws. The invention is simple and has high gain, meets the requirements of the 6A type high gain, and the simple circuit structure makes the manufacturing and installation convenient and fast.

Description

Technical Field

[0001] The invention relates to the field of power amplifiers, and in particular to a 6A type high-gain amplifier module and a manufacturing method thereof. Background Art

[0002] With the continuous development of modern electronic technology, integrated circuits are widely used in various electronic circuits. With the advancement of semiconductor technology in the past decade, power amplifier circuits have also been rapidly developed and applied, and the requirements for power amplifiers are getting higher and higher.

[0003] The 6A type power amplifier is one of the important components of ground radar and is widely used in military aspects. Therefore, high performance requirements are imposed on it. At present, the common problems of the 6A type power amplifier are low precision, susceptibility to interference from the external environment, high cost, low gain, low output signal peak power, load open circuit damage, large pulse top drop, and uncontrollable effective range of the output pulse signal leading edge and lower trailing edge time. At the same time, there is no simple and efficient manufacturing method for the manufacture of the 6A type power amplifier in the prior art, and the manufacturing process is also very important for the power output and stability of the power amplifier. Therefore, it is urgent to design a 6A type high gain amplifier module and provide a new manufacturing method to solve any of the above technical problems. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a 6A type high gain amplifier module and a manufacturing method thereof. The amplifier module has a simple circuit structure, high gain and low cost. At the same time, the module manufacturing method provided meets the requirements of mass production.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a 6A type high-gain amplifier module, which includes resistors R1~R38, power amplifier tubes U2, U4, U6, diodes U5, U8, U13, U14, D1, D2, D3, triodes U11, U12, U22, U23, isolator U7, potentiometers U10, U20, and inductors L1, L2, L3, L4, chips U1, U3, U9, U15, U16, U17, U18, U19, U21.

[0006] The chip U1 is a temperature compensated attenuator, one end of the chip U1 is connected to the input port, and the other end is connected to the capacitor C1 and the power supply; the capacitors C1 and C2 are connected in series, and the resistor R26 is connected in parallel with the capacitors C1 and C2 to form a high-pass filter to obtain impedance matching;

[0007] One end of the power amplifier tube U2 is connected to the capacitor C2, and the other end thereof is connected to the capacitor C3 and the inductor L1, so as to perform a pre-amplification function on the input signal;

[0008] The chip U3 is a temperature compensated attenuator, one end of the chip U3 is connected to the capacitor C4, and the other end is connected to the capacitor C8;

[0009] The chip U5 is a PIN diode, and the function of the PIN diode gain adjustment is to adjust the output power; the pin 1 of the chip U5 is connected to the capacitor C8, the pin 2 of the chip is connected to the resistor R28, and the pin 3 is connected to the capacitor C9 and the inductor L4, and the capacitor C9 and the inductor L4 are connected in parallel to form an LC circuit;

[0010] One end of the power amplifier tube U4 is connected to the capacitor C10 for isolation and filtering, and the other end is connected to the capacitor C11 and the inductor L2 to form an LC circuit;

[0011] One end of the power amplifier tube U6 is connected to the capacitor C11, which plays the role of isolation protection filtering, and is also connected to the 5th and 6th pins of the chip U17, and the other end is connected to the capacitor C12 and is also connected to the 5th and 6th pins of the chip U17;

[0012] The isolator U7 end is connected to the capacitor C12, and the other end is connected to the output interface RF-OUT;

[0013] The chip U9 is a comparator, pin 1 of the chip U9 is connected to R9, pin 2 of the chip is connected to resistors R10 and R11 respectively, pin 3 of the chip is connected to the other end of R11 and resistor R12 respectively, pin 4 of the chip is connected to the positive electrode of capacitor C14 and resistor R21 respectively, pin 5 of the chip is connected to the negative electrode of capacitor C15 and ground respectively, pin 6 of the chip is connected to the positive electrode of capacitor C15 and the other end of resistor R12 respectively, pin 7 of the chip is connected to potentiometer U10, and pin 8 of the chip is connected to resistor R13;

[0014] The chip U19 is an operational amplifier chip, which changes the +15V voltage at the input end to +10V. Pin 1 of the chip U19 is connected to capacitor C28 and resistor R21 respectively, pin 2 of the chip is connected to the other end of resistor R21, pin 3 of the chip is connected to resistor R28, pin 4 of the chip is connected to the other end of capacitor C28 and diode D1 respectively, the positive electrode of capacitor C27, ports 1 and 2 of the DB9 connector port, the positive electrodes of capacitors C16 to C21 and one end of the chip U18 are connected;

[0015] The chip U18 is a voltage stabilizing chip, which converts the +10V voltage output by the chip U9 into +5V. One end of the chip is connected to pin 4 of chip U19, pin 6 of chip U15 and pin 4 of chip U9, and the other end is connected to pin 4 of chip U21, pin 6 of chip U16 and pin 2 of chip U17.

[0016] The chips U15 and 16 are inverters that invert the input TTL level signal, and the amplitude is the power supply voltage required by the power amplifier tube U6. One end of the chips U15 and U16 is connected to the 2nd and 3rd pins of the chip U17 respectively, and the other end is connected to the chip U18;

[0017] The chip U17 is a MOS tube chip, the G level of the MOS tube is connected to the output of the inverters U15 and U16, the S level of the MOS tube is connected to the power supply voltage chip U18, and the output end of the MOS tube is connected to the power amplifier tube U6, thereby completing power supply modulation.

[0018] The chip U21 is a power conversion chip, which converts the +5V voltage into -5V, and then divides the -5V voltage through the resistor R30 to supply power to the gate of the power amplifier tube U6; the pin 1 of the chip U21 is respectively connected to the capacitor C37 and the ground, the pin 3 of the chip is respectively connected to the diode D3, the other end of the capacitor C37 and the pin 2 of the chip, the pin 4 of the chip is respectively connected to the diode D2 and the inductor L3, the pin 5 of the chip is respectively connected to the capacitor C38 and the pin 7 of the chip, and the pin 8 of the chip is respectively connected to the other end of the diode D2 and the resistor R32.

[0019] A method for manufacturing a 6A type high gain amplifier module comprises the following steps:

[0020] Step 1: Prepare the cavity, circuit board, pressure strip, cover plate, and degrease, clean and smooth the corresponding structural parts;

[0021] Step 2: Process the high-gain amplifier circuit board. First, apply solder paste on the welding points of the circuit board, then attach each component to the welding points, and finally perform sintering.

[0022] Step 3: Clean the circuit board, remove the dirt layer and air dry;

[0023] Step 4: Clean the cavity and cover plate;

[0024] Step 5: Solder the components to the circuit board;

[0025] Step 6: Clean the circuit board with components, remove the dirt layer and air dry;

[0026] Step 7: Soldering of leads;

[0027] Step 8: Installation of the circuit board;

[0028] Step 9: Assemble the isolator, power amplifier chip, and voltage regulator chip on the cavity and solder them. After the circuit board is fixed in the cavity, start installing the final power amplifier chip, isolator, power conversion chip, and soldering them;

[0029] Step 10: Assemble the SMA connector, DB9 connector and pressure strip;

[0030] Step 11: Preliminary debugging of 6A type high gain amplifier;

[0031] Step 12: Capping.

[0032] The step 3 comprises: placing the circuit board of the high-gain amplifier in step 2 in a cleaning solution, soaking it for 5 minutes, observing whether there is any soldering residue such as solder paste under a microscope, and if so, repeatedly cleaning it, and finally wiping it with alcohol cotton dipped in anhydrous ethanol, and placing it in an antistatic box after it is naturally dried.

[0033] The cavity and cover cleaning of step 4 includes: placing the cavity and cover processed in step 1 into a plasma cleaning machine, cleaning for half an hour, air-drying naturally, and then placing them into an antistatic box.

[0034] The specific operation method of step 5 is as follows:

[0035] Step 5.1: Apply a proper amount of solder paste on the circuit board, mount the components to the pads, and place resistors R1~R38, diodes U5, U8, U13, U14, D1, D2, D3, transistors U11, U12, U22, U23, and inductors L1, L2, L3, L4 on the solder paste;

[0036] Step 5.2: Turn on the power switch of the heating platform for preheating, set the temperature to 250±5℃, place the circuit board with the components attached on the heating platform for sintering. After sintering, remove it with pointed tweezers, place it on the heat sink, and cool it to room temperature;

[0037] Step 5.3: After the temperature of the soldering iron tip reaches 300℃±10℃ using a thermometer, solder and adjust the position of some components.

[0038] The specific operation method of step 6 is as follows: put the finished circuit board in step 5 into the plasma cleaning machine, take it out after cleaning for ten minutes, and then observe under a microscope whether there is any welding residue such as solder paste attached, and finally wipe it with alcohol cotton dipped in anhydrous ethanol, wait for it to dry naturally, and then put it in an anti-static box.

[0039] The specific operation method of step 8 is as follows:

[0040] Step 8.1 Before installation, use an air gun to blow the circuit board and cavity to keep them dry and free of foreign matter;

[0041] Step 8.2 uses round head steel screws M2×6, and uses them together with M2 springs and washers to ensure that each screw is installed firmly and firmly, so that the circuit board is in full contact with the ground.

[0042] The specific operation method of step 9 is as follows:

[0043] Step 9.1 Install the power amplifier tubes U2, U4, U6, isolator U7, chips U1, U3, U9, U15, U16, U17, U18, U19, U21 and solder them;

[0044] Step 9.2 Solder on an anti-static protection table. Avoid touching the device pins directly with your hands during this process. Use a thermometer to measure the temperature of the soldering iron tip until it reaches 350℃±10℃. When soldering, control the soldering time. The soldering time for each pin is generally controlled within 5 seconds.

[0045] Step 9.3 Install the device horizontally against the printed circuit board, press the chip lightly with your hands to ensure that it is installed firmly and fully; and reinforce the device with glue, and reinforce the solder joints with glue;

[0046] Step 9.4 After welding, use a brush dipped in anhydrous ethanol to remove the rosin flux left over from welding and dry it.

[0047] The advantages of the present invention are: the circuit structure is simple and the gain is high, which meets the requirements of 6A type high gain. The simple circuit structure makes the production and installation convenient and fast, and can be mass-produced. The production method is simple, and it has the characteristics of low cost, short cycle, stability, etc., which provides a strong guarantee for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0049] Figure 1 The circuit diagram of the 6A type high gain amplifier is shown in FIG.

[0050] Figure 2 This is the actual circuit layout of the 6A type high gain amplifier;

[0051] Figure 3 The isolation strip physically isolates the RF circuit from the power circuit, increases the stability of the power amplifier, and reduces the interference between the RF circuit and the power control circuit;

[0052] Figure 4 Power Amplifier Assembly Drawing DETAILED DESCRIPTION

[0053] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0054] The 6A type high gain amplifier module and its manufacturing method of the present invention have been tested and manufactured for many times, and the products produced by this manufacturing method have been tested and debugged as a whole machine. All performance indicators can meet the requirements of the whole machine. The manufacturing method is simple, with low investment and high reliability, and is suitable for small batch production. The specific scheme is as follows:

[0055] like Figure 1 As shown, this is the circuit schematic diagram of the 6A high-gain amplifier module of the present application, and its circuit structure specifically includes: resistors R1~R38, power amplifier tubes U2, U4, U6, diodes U5, U8, U13, U14, D1, D2, D3, transistors U11, U12, U22, U23, isolator U7, potentiometers U10, U20, and inductors L1, L2, L3, L4, chips U1, U3, U9, U15, U16, U17, U18, U19, U21.

[0056] The chip U1 is a temperature-compensated attenuator. In order to ensure the flatness of the output power in the full temperature range and the full frequency range, a temperature-compensated attenuator is added to the input end to balance the gain of high and low temperatures. One end of the chip U1 is connected to the input port, and the other end is connected to the capacitor C1 and the power supply. At the same time, capacitors C1 and C2 are connected in series, and resistor R26 is connected in parallel with capacitors C1 and C2 to form a high-pass filter to obtain suitable impedance matching;

[0057] One end of the power amplifier tube U2 is connected to the capacitor C2, and the other end thereof is connected to the capacitor C3 and the inductor L1, so as to perform a pre-amplification function on the input signal;

[0058] The chip U3 is a temperature compensated attenuator, one end of the chip U3 is connected to the capacitor C4, and the other end is connected to the capacitor C8;

[0059] The chip U5 is a PIN diode, and the function of the PIN diode gain adjustment is to adjust the output power, and at least adjust the power output to reduce by 2dB. The 1st pin of the chip U5 is connected to the capacitor C8, the 2nd pin of the chip is connected to the resistor R28, and the 3rd pin is connected to the capacitor C9 and the inductor L4. The capacitor C9 and the inductor L4 are connected in parallel to form an LC circuit;

[0060] One end of the power amplifier tube U4 is connected to the capacitor C10 to play the role of isolation and filtering, and the other end is connected to the capacitor C11 and the inductor L2 to form an LC circuit;

[0061] One end of the power amplifier tube U6 is connected to the capacitor C11, which plays the role of isolation protection filtering, and is also connected to the 5th and 6th pins of the chip U17, and the other end is connected to the capacitor C12 and is also connected to the 5th and 6th pins of the chip U17;

[0062] One end of the isolator U7 is connected to the capacitor C12 to play the role of isolation protection and filtering, and the other end is connected to the output. The isolator can ensure that the power amplifier has the ability to be open-circuited without being damaged.

[0063] The chip U9 is a comparator, which can complete the circuit fault alarm by comparing the voltage output by the detector diode. Pin 1 of the chip U9 is connected to R9, pin 2 of the chip is connected to resistors R10 and R11 respectively, pin 3 of the chip is connected to the other end of R11 and resistor R12 respectively, pin 4 of the chip is connected to the positive electrode of capacitor C14 and resistor R21 respectively, pin 5 of the chip is connected to the negative electrode of capacitor C15 and the ground respectively, pin 6 of the chip is connected to the positive electrode of capacitor C15 and the other end of resistor R12 respectively, pin 7 of the chip is connected to potentiometer U10, and pin 8 of the chip is connected to resistor R13;

[0064] The chip U19 is an operational amplifier chip, which changes the +15V voltage at the input end to +10V. Pin 1 of the chip U19 is connected to capacitor C28 and resistor R21 respectively, pin 2 of the chip is connected to the other end of resistor R21, pin 3 of the chip is connected to resistor R28, pin 4 of the chip is connected to the other end of capacitor C28 and diode D1 respectively, the positive electrode of capacitor C27, ports 1 and 2 of the DB9 connector port, the positive electrodes of capacitors C16 to C21 and one end of the chip U18 are connected;

[0065] The chip U18 is a voltage stabilizing chip, which converts the +10V voltage output by the chip U9 into +5V. One end of the chip is connected to pin 4 of chip U19, pin 6 of chip U15 and pin 4 of chip U9, and the other end is connected to pin 4 of chip U21, pin 6 of chip U16 and pin 2 of chip U17.

[0066] The chips U15 and 16 are inverters that invert the input TTL level signal, and the amplitude is the power supply voltage required by the power amplifier tube U6. One end of the chips U15 and U16 is connected to the 2nd and 3rd pins of the chip U17 respectively, and the other end is connected to the chip U18;

[0067] The chip U17 is a MOS tube chip, the G level of the MOS tube is connected to the output of the inverters U15 and U16, the S level of the MOS tube is connected to the power supply voltage chip U18, and the output end of the MOS tube is connected to the power amplifier tube U6, thereby completing power supply modulation.

[0068] The chip U21 is a power conversion chip, which converts +5V voltage into -5V, and then divides the -5V voltage through resistor R30 to supply power to the gate of the power amplifier tube U6. Pin 1 of chip U21 is connected to capacitor C37 and ground respectively, pin 3 of chip is connected to diode D3, the other end of capacitor C37 and pin 2 of chip respectively, pin 4 of chip is connected to diode D2 and inductor L3 respectively, pin 5 of chip is connected to capacitor C38 and pin 7 of chip respectively, and pin 8 of chip is connected to the other end of diode D2 and resistor R32 respectively.

[0069] A method for manufacturing a 6A type high gain amplifier module comprises the following steps:

[0070] Step 1: Prepare the cavity, circuit board, pressure strip, cover plate, and degrease, clean and smooth the corresponding structural parts;

[0071] Step 2: Process the high-gain amplifier circuit board. First, apply solder paste on the welding points of the circuit board, then attach each component to the welding points, and finally perform sintering.

[0072] Step 3: Clean the circuit board, remove the dirt layer and air dry;

[0073] Step 4: Clean the cavity and cover plate;

[0074] Step 5: Solder the components to the circuit board;

[0075] Step 6: Clean the circuit board with components, remove the dirt layer and air dry;

[0076] Step 7: Welding of the lead wires. The welding time and temperature should be controlled during welding. The welding time is generally controlled within 5 seconds, and all welding is performed on an anti-static protection table;

[0077] Step 8: Install the circuit board. Use round head steel screws M2×6, and use them together with M2 springs and washers to ensure that each screw is installed firmly and firmly, so that the circuit board can fully contact the ground;

[0078] Step 9: Assemble the isolator, power amplifier chip, and voltage regulator chip on the cavity and weld them. After the circuit board is fixed in the cavity, start to install the final power amplifier chip, isolator, and power conversion chip and weld them. When installing the power amplifier chip, it should be installed firmly and fully, which will help the heat of the chip to dissipate easily, increase the heat dissipation speed of the power chip, and play a great role in improving the reliability and stability of the power amplifier;

[0079] Step 10: Assemble the SMA connector, DB9 connector and pressure strip;

[0080] Step 11: Preliminary debugging of the 6A type high gain amplifier.

[0081] Step 12: Cover; Place the cover on the cavity and secure it with M1.6 flat head screws.

[0082] Step 3 includes: placing the circuit board of the high-gain amplifier in step 2 in a cleaning solution, soaking it for 5 minutes, and then observing under a microscope whether there are solder paste and other welding residues. If so, repeatedly cleaning it, and finally wiping it with alcohol cotton dipped in anhydrous ethanol, and placing it in an anti-static box after it is naturally dried.

[0083] The cavity and cover cleaning in step 4 includes: placing the cavity and cover processed in step 1 into a plasma cleaning machine, cleaning for half an hour, drying naturally, and then placing them in an anti-static box.

[0084] The specific operation method of step 5 is as follows:

[0085] Step 5.1: Apply a proper amount of solder paste on the circuit board, mount the components to the pads, and place resistors R1~R38, diodes U5, U8, U13, U14, D1, D2, D3, transistors U11, U12, U22, U23, and inductors L1, L2, L3, L4 on the solder paste;

[0086] Step 5.2: Turn on the power switch of the heating platform for preheating, set the temperature to 250±5℃, place the circuit board with the components attached on the heating platform for sintering. After sintering, remove it with pointed tweezers, place it on the heat sink, and cool it to room temperature;

[0087] Step 5.3: After the temperature of the soldering iron tip reaches 300℃±10℃ using a thermometer, solder and adjust the position of some components.

[0088] The specific operation method of step 6 is as follows: put the finished circuit board in step 5 into the plasma cleaning machine, take it out after cleaning for ten minutes, and then observe under a microscope whether there is any welding residue such as solder paste attached, and finally wipe it with alcohol cotton dipped in anhydrous ethanol, wait for it to dry naturally, and then put it in an anti-static box.

[0089] The specific operation method of step 8 is as follows:

[0090] Step 8.1 Before installation, use an air gun to blow the circuit board and cavity to keep them dry and free of foreign matter;

[0091] Step 8.2 uses round head steel screws M2×6, and uses them together with M2 springs and washers to ensure that each screw is installed firmly and firmly, so that the circuit board is in full contact with the ground.

[0092] The specific operation method of step 9 is as follows:

[0093] Step 9.1 Install the power amplifier tubes U2, U4, U6, isolator U7, chips U1, U3, U9, U15, U16, U17, U18, U19, U21 and solder them;

[0094] Step 9.2 Solder on an anti-static protection table. Avoid touching the device pins directly with your hands during this process. Use a thermometer to measure the temperature of the soldering iron tip until it reaches 350℃±10℃. When soldering, control the soldering time. The soldering time for each pin is generally controlled within 5 seconds.

[0095] Step 9.3 Install the device horizontally against the printed circuit board, press the chip lightly with your hands to ensure that it is installed firmly and fully; and reinforce the device with glue, and reinforce the solder joints with glue;

[0096] Step 9.4 After welding, use a brush dipped in anhydrous ethanol to remove the rosin flux left over from welding and dry it.

[0097] Step 10: Assemble the SMA connector, DB9 connector and isolation strip. Pay special attention to aligning the SMA connector with the microstrip line during installation. If the microstrip line is thin, use a scalpel to scrape the copper sheet around it that is not covered with circuit wiring to make the contact more complete. Finally, use M2.5 round head screws to fix it.

[0098] Step 11: Perform preliminary debugging on the 6A type high gain amplifier without a cover. The specific performance of debugging is that the output power is 6W and the in-band fluctuation is less than 0.5dBm. The specific debugging method is to touch the entire RF microstrip line with the index finger. When there is a certain effect change, use the 0603 package military capacitor to weld the touch position, and repeatedly debug until the technical indicators are met. The size of the military capacitor depends on the actual application effect, but its capacitance does not exceed 10pF.

[0099] Step 12: Cover; Place the cover on the cavity and secure it with screws.

[0100] At this point, the production of a 6A high-gain amplifier module is completed.

[0101] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A 6A high gain amplifier module, characterized in that: The amplifier module includes resistors R1 to R38, power amplifier tubes U2, U4, U6, diodes U5, U8, U13, U14, D1, D2, D3, triodes U11, U12, U22, U23, isolator U7, potentiometers U10, U20, and inductors L1, L2, L3, L4, chips U1, U3, U9, U15, U16, U17, U18, U19, U21; The chip U1 is a temperature compensated attenuator, one end of the chip U1 is connected to the input port, and the other end is connected to the capacitor C1 and the power supply; the capacitors C1 and C2 are connected in series, and the resistor R26 is connected in parallel with the capacitors C1 and C2 to form a high-pass filter to obtain impedance matching; One end of the power amplifier tube U2 is connected to the capacitor C2, and the other end thereof is connected to the capacitor C3 and the inductor L1, so as to perform a pre-amplification function on the input signal; The chip U3 is a temperature compensated attenuator, one end of the chip U3 is connected to the capacitor C4, and the other end is connected to the capacitor C8; The chip U5 is a PIN diode, and the gain adjustment function of the PIN diode is to make the output power adjustable; Pin 1 of chip U5 is connected to capacitor C8, pin 2 of chip is connected to resistor R28, and pin 3 of chip U5 is connected to capacitor C9 and inductor L4. Capacitor C9 and inductor L4 are connected in parallel to form an LC circuit. One end of the power amplifier tube U4 is connected to the capacitor C10 for isolation and filtering, and the other end is connected to the capacitor C11 and the inductor L2 to form an LC circuit; One end of the power amplifier tube U6 is connected to the capacitor C11, which plays the role of isolation protection filtering, and is also connected to the 5th and 6th pins of the chip U17, and the other end is connected to the capacitor C12 and is also connected to the 5th and 6th pins of the chip U17; The isolator U7 end is connected to the capacitor C12, and the other end is connected to the output interface RF-OUT; The chip U9 is a comparator, pin 1 of the chip U9 is connected to the resistor R9, pin 2 of the chip U9 is connected to the resistor R10 and the resistor R11 respectively, pin 3 of the chip U9 is connected to the other end of the resistor R11 and the resistor R12 respectively, pin 4 of the chip U9 is connected to the positive electrode of the capacitor C14 and the resistor R21 respectively, pin 5 of the chip U9 is connected to the negative electrode of the capacitor C15 and the ground respectively, pin 6 of the chip U9 is connected to the positive electrode of the capacitor C15 and the other end of the resistor R12 respectively, pin 7 of the chip U9 is connected to the potentiometer U10, and pin 8 of the chip U9 is connected to the resistor R13; The chip U19 is an operational amplifier chip, which converts the +15V voltage at the input end into +10V; Pin 1 of chip U19 is connected to capacitor C28 and resistor R21 respectively, pin 2 of chip U19 is connected to the other end of resistor R21, pin 3 of chip U19 is connected to resistor R28, pin 4 of chip U19 is connected to the other end of capacitor C28 and diode D1 respectively, the positive electrode of capacitor C27, ports 1 and 2 of DB9 connector, positive electrodes of capacitors C16 to C21 are connected to one end of chip U18; The chip U18 is a voltage stabilizing chip, which converts the +10V voltage output by the chip U9 into +5V. One end of the chip U18 is connected to the 4th pin of the chip U19, the 6th pin of the chip U15 and the 4th pin of the chip U9, and the other end of the chip U18 is connected to the 4th pin of the chip U21, the 6th pin of the chip U16 and the 2nd pin of the chip U17. The chips U15 and 16 are inverters, which invert the input TTL level signal, and the amplitude thereof is the power supply voltage required by the power amplifier tube U6; One end of chips U15 and U16 is connected to pins 2 and 3 of chip U17 respectively, and the other end is connected to chip U18; The chip U17 is a MOS tube chip, the G level of the MOS tube is connected to the output of the inverters U15 and U16, the S level of the MOS tube is connected to the power supply voltage chip U18, and the output end of the MOS tube is connected to the power amplifier tube U6, thereby completing power supply modulation; The chip U21 is a power conversion chip, which converts the +5V voltage into -5V, and then divides the -5V voltage through the resistor R30 to supply power to the gate of the power amplifier tube U6; the pin 1 of the chip U21 is respectively connected to the capacitor C37 and the ground, the pin 3 of the chip is respectively connected to the diode D3, the other end of the capacitor C37 and the pin 2 of the chip, the pin 4 of the chip is respectively connected to the diode D2 and the inductor L3, the pin 5 of the chip is respectively connected to the capacitor C38 and the pin 7 of the chip, and the pin 8 of the chip is respectively connected to the other end of the diode D2 and the resistor R32.

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