Characterization of third-order nonlinearity in low noise amplifier

This paper presents the characterization of third-order nonlinearity in low noise amplifiers (LNAs). The nonlinearities including harmonic distortion, gain compression, cross modulation, intermodulation, blocking, desensitization and etc. In this paper, the focus is on the third-order nonlinearity. A double frequency signal injection method-which the dual-signal is with different frequency sweeping rate-is developed to characterize the nonlinearity. The measurement results demonstrated that all the linear and nonlinear signal paths and effects can be extracted.