Circuit capable of realizing reception link rapid gain adjustment through adoption of open loop mode

The utility model relates to a circuit capable of realizing reception link rapid gain adjustment through adoption of an open loop mode. The circuit comprises a wave detecting circuit, two hysteresis comparators, two groups of single-pole double-throw switches, an n-shaped attenuator and a radio frequency amplifier U2, wherein the wave detecting circuit consists of a wave detector U1 and the like; the two hysteresis comparators consist of an operational amplifier U3A, an operational amplifier U3B and the like; the two groups of single-pole double-throw switches consist of a PIN tube D1, a PIN tube D2, a PIN tube D3 and a PIN tube D4; the n-shaped attenuator consists of a resistor R17, a resistor R19 and a resistor R20. The circuit is extremely high in overall gain adjustment responding speed and is characterized by high speed, small time delay, low power consumption, convenient debugging, good circuit stability, simple circuit structure, high reliability and the like. The circuit is specially applied to received signal power adjustment in design of the front ends of receiving machines on high speed moving carriers of flights, navigations and the like.