ANALYSIS OF MODULATOR CIRCUITS BASED ON MULTI-DIMENSIONAL FOURIER TRANSFORMATION

There are many communication circuits driven by multi-tone signals such as modulator and mixer. If the input frequency components are largely dHferent in each other, the brute force numerical method will take an enormous comput at ion time to get the steady-state responses. In this paper, we show a SPICE oriented algorithm based on multi-dimensional Fourier transformation, where all of the circuit analyses such as dc- and at-analysis in the al-gorithm are carried out with SPICE. On the other hand, a very simple sensitivity analysis and 2-dimensional FFT are carried out by a Fortran program (or C program). We found that the convergence ratio of our algorithm is sufficiently large, and can be applied to wide class of com-municant ion circuits. 1