Abstract: A cascode amplifier circuit having substantial linearity, while maintaining other advantages of cascode amplifiers such as relatively high input-to-output isolation and relatively high gain. The cascode amplifier circuit also provides substantially matched impedance between input and output, at least within a selected frequency band, with the effect of providing a circuit that is well-suited for use in a communication system. The cascode amplifier circuit includes feedback loops, such as for example DC feedback loops and AC feedback loops, and bias optimization, with the effect of improving linearity, maintaining gain, minimizing return loss, and providing a relatively high dynamic range.