Low-noise amplifier

A low-noise amplifier for receiving and amplifying a RF signal from a RF signal source to output an amplified signal, comprising:

• a first switch equipped with an input node and a first and a second output nodes for receiving the RF signal through the input node and outputting the RF signal through either the first or the second output node;
• a first amplifying circuit comprising an amplifying stage, an input impedance matching circuit disposed between the first output node of said first switch and an input terminal of said amplifying stage, and an output impedance matching circuit disposed between an output terminal of said amplifying stage and an input node of combining means;
• a redundancy circuit having an input terminal connected to the second output node of said first switch;
• said combining means equipped with the first input node connected to an output terminal of said first amplifying circuit and a second input node connected to an output terminal of said redundancy circuit for combining signals received through the first and the second input nodes to output a combined signal through an output node;
• and
• a control signal generator for monitoring a status of said first amplifying circuit and generating a switching control signal of which state changes according to a monitored result,
• wherein the input node of said first switch is electrically connected to the first output node when the first amplifying circuit operates normally and the switching control signal is at a first state, and is connected to the second output node when the first amplifying circuit operates abnormally and the switching control signal is at a second state.