For those interested in creating accurate models for large-signal devices and circuits, modeling experts Modelithics now offer X-parameter measurement and modeling services. The company, which is celebrating its 10th anniversary this month, uses a PNA-X Series nonlinear vector network analyzer (VNA) from Agilent Technologies to make the measurements and develop X-parameters, which are essentially nonlinear extensions of scattering (S) parameters used extensively through the high-frequency industry for circuit design.

The use of X-parameters provides greater insight into nonlinear effects in such circuits as amplifiers, mixers, and integrated circuits, predicting the behavior of harmonics, intermodulation distortion, and impedance mismatches at RF and microwave frequencies.