Properties of FET parameter statistical data bases

Statistical databases are often used to characterize the statistics of a FET. It is shown that a database containing the FET model parameter marginal probability density functions and covariance matrix is not sufficient to describe the FET's S-parameter statistics. This result is important to those developing statistical databases for GaAs FETs. The implications of this work for simulation and CAD are discussed, and a solution to this problem, the truth model, is presented.<<ETX>>