Fast rigorous analysis of shielded planar filters

It is shown that realistically complex microstrip circuits can be rigorously analyzed on a small computer by means of the spectral domain technique in combination with precomputed basis functions and the use of the asymptotic forms of the Green's function and the fast Fourier transform (FFT) algorithm. The results compare well with published measurements and with calculations using finite-difference time-domain (FDTD) method. >