X-parameter-based frequency doubler design

As a kind of superset of S-parameters, X-parameters are becoming increasingly popular in non-linear device simulation and measurement. Due to their good accuracy and convenient extraction procedures, X-parameter-based transistor device models have so far been mainly used in power amplifiers design. They have been limited to this kind of design up to now because the X-parameter models extracted are only suitable for fundamental frequency circuit design. In this paper, a new extraction method is described to allow the extracted model to be used to designing a frequency doubler, and verification through simulation results is presented.