Circuit optimization with X-parameter models

Abstract

X-parameter technology is now established as an indispensable methodology for accurate characterization and modeling of nonlinear components and sub-circuits. However, important considerations may be overlooked when such models are used for optimizing the designs. This paper discusses circuit optimization issues when X-parameter models are employed. This includes the characterization and extraction requirements, interpolation and extrapolation issues, scaling, embedding, as well as potential modification of the components characterized by X-parameter data. Examples include amplifier and transistor designs for power delivered into the load, PAE and linearity performance criteria.