Analysis of intermodulation nulling in HEMTs

Abstract

This paper examines intermodulation nulling generated by the nonlinear current voltage characteristics of HEMTs. The conditions for iintermodulation cancellation in terms of the coefficients of a two-dimensional Taylor's series expansion are established and verified with measurement and simulation. Second and third-order intermodulation cancellation can be assessed by simple examination of the transconductance characteristics of the device. This permits routine selection of optional bias after characterising the devices.