Amplifier circuit, especially low-noise amplifier, with passive gain-step stage has device for switching off amplifier and switching on coupler if level of input signal exceeds threshold value

摘要

The amplifier circuit has an amplifier (22) between an HF input (26) and an HF output (28), a coupler (24) parallel to the amplifier with an input coupling bipolar transistor (T1) and an output coupling diode structure and a device for switching off the amplifier and switching on the coupler if the level of the input signal exceeds a threshold value.