Low noise amplifier

A low noise amplifier, comprising:

• a controller configured to detect a power level of an input RF signal and output a corresponding switching control signal;
• an RF switch configured to switch the input RF signal according to the switching control signal;
• a positive gain amplifier connected to the RF switch and configured to amplify the input RF signal and output the amplified RF signal;
• an attenuator connected to the RF switch and configured to attenuate the input RF signal and output the attenuated RF signal;
• and
• a phase difference matching unit connected to an output of the attenuator and implemented as a circuit having the same phase difference as the positive gain amplifier.