This paper proposes a measurement setup for analyzing and measuring the nonlinearity and memory effects in active power device as well as power amplifier (PA). In order to reduce the memory effect in the measurement data, new dynamic measurement setup with combination of two bias tees is developed for realizing short termination at envelope frequencies. Furthermore, for full automatic control of the measurement setup, controlling software using Agilent VEE programming software is developed. Moreover, measurement of envelope frequency dependent nonlinearity in GaN HEMT power device is presented