"宽带可控增益射频放大器设计及实现报告"

le gain amplifiers VCA822 as the main amplifier, and the rear stage AD8009 to build the main amplifier circuit, realizing a broadband controllable gain RF amplifier. VCA822 performs programmable amplification on the input signal of the front stage, the rear stage AD8009 adjusts the output to meet power requirements, and impedance matching is carried out. The microcontroller, keypad, and display module achieve digital gain control, with a user-friendly interface. To reduce ripple interference and improve signal-to-noise ratio, a high-precision low-ripple linear power supply is designed to power the amplification circuit and microcontroller. The entire system has strong stability and interference resistance. The system is easy to assemble and has been tested to meet the project requirements. Keywords: high-frequency broadband amplifier, microcontroller, STC89C52, OP820, AD8009, VCA822 In conclusion, the design of a high-frequency broadband amplifier using STC89c52 as the control core, VCA822 and AD8009 as the main amplifiers, has successfully achieved a wideband controllable gain RF amplifier. The use of programmable amplification and impedance matching has improved the performance of the amplifier. The integration of a microcontroller, keypad, and display module has created a user-friendly interface for easy control of the amplifier. The design of a high-precision low-ripple linear power supply has effectively reduced interference and improved the signal-to-noise ratio of the system. Overall, the system exhibits strong stability and interference resistance, and has been tested to meet project requirements.