Low noise amplifier and method of input impedance control for terrestrial and cable modes

摘要

A low noise amplifier (LNA) for use in a receiver circuit includes an adjustable impedance network including an input for receiving a radio frequency signal, a plurality of control inputs, and an output. The LNA further includes a controller coupled to the plurality of control inputs and configured to control an impedance of the adjustable impedance network. The controller controls the adjustable impedance network to provide a relatively low impedance in a terrestrial mode and to provide a relatively high impedance in a cable mode.