Characterization of power amplifier inter-modulation nonlinearity using multisine-based nonlinear vector network analyzer

This paper uses multisines and a vector network analyzer (VNA) to achieve a dense-spectral-grid Nonlinear-VNA (NVNA) testbed, so that the inter-modulation nonlinearity of a RF power amplifier can be well characterized in the frequency domain. The multisine signals are provided by vector signal generators, and are used as both the NVNA phase reference and the modulated test stimulus. Based on these frequency-domain measurement results, the nonlinear behavior of the power amplifier under test can be analyzed in frequency, time and envelope domains.