Nonlinear RF device modelling in the presence of low-frequency dispersive phenomena

Theoretical and practical issues concerning the non-linear dynamic modelling of electron devices are discussed in this paper. All the different dynamic phenomena, which are important for the description of the device behaviour, are comprehensively dealt with by means of a unified mathematical derivation. In particular, both the "fast" dynamics associated with charge-storage phenomena at high operating frequencies and the "slow" dynamics of low-frequency dispersion, due to device self-heating and charge-"trapping" effects in deep-bulk and surface regions, are simultaneously taken into account. The result is an empirical, technology-independent and non quasi-static model of electron devices, suitable for a simple and reliable identification procedure based on conventional measurements of static characteristics and bias- and frequency- dependent small-signal parameters. The model implementation in the framework of commercially available CAD tools is also outlined in the paper. Experimental validation, based on a GaAs p-HEMT, is also presented.