Spline-based behavioural model for efficient analysis of large front-ends for W-CDMA systems

A new behavioural model suitable for the analysis of RF front-ends for W-CDMA systems is described. The model fully accounts for both linear and nonlinear dispersion effects, so that relatively by a band digitally modulated signals can be accurately dealt with. The linear front-end response is computed by means of the conversion admittance matrix. The relationship between the linear and nonlinear responses is characterised by a voltage and frequency-dependent describing function. The latter is evaluated by a cubic-spline-based two-dimensional interpolation scheme starting from a database generated by harmonic-balance analysis. In this way, front-end simulations that would require months of CPU time even by modern envelope-oriented techniques, can be performed in a matter of seconds without significant loss of accuracy.