RF gain adjusting circuit

The invention discloses an RF (radio frequency) gain adjusting circuit which comprises, sequentially connected, a button circuit, an MCU chip, a control voltage circuit and a gain controlled circuit. The RF gain adjusting circuit further comprises a power supply circuit, a clock circuit and a display circuit, wherein the signal input end of the gain controlled circuit receives RF incoming signals, the signal output end of the gain controlled circuit emits RF output signals, a data module and a digital analog converter or pulse-width modulation device are arranged in the MCU chip, the data module is connected with the digital analog converter or the pulse-width modulation device, and data corresponding to input control voltage values for different gains on the gain controlled circuit are stored in the data module. The display circuit displays gains, and directly and accurately displays RF gain adjustment, and the control signals of the gain controlled circuit are completed by the MCU chip and related circuits. Change of the gains of the gain controlled circuit due to the change of the position of an adjustable potentiometer under informed situation can be prevented.