A mode-switching LNA generally includes an input unit, an output unit and a bias voltage generator. The input unit amplifies an input signal to generate an amplified signal. The output unit receives the amplified signal from the input unit and operates either in an oscillation mode or in an amplification mode in response to a control signal to generate an output signal having a center frequency equal to a target frequency. The control signal indicates whether the center frequency of the output signal is the same as the target frequency. The bias voltage generator provides an input bias voltage to the input unit in response to the control signal, where the input bias voltage includes a first bias voltage in the amplification mode and a second bias voltage in the oscillation mode.