A low noise amplifier is provided. The low noise amplifier includes an input port, an output port, an inverter, a plurality of switched-capacitor units and a feedback inductor. The inverter is electrically connected between the input port and the output port. Each of the plural switched-capacitor units is electrically connected with the inverter in parallel and includes a switch and a capacitor connected in series. The feedback inductor is electrically connected with the inverter in parallel.