Electromagnetic analysis of complex microstrip structures using a CG-FFT scheme

This work presents the extensions required in a Conjugate Gradient Fast Fourier Transform (CG-FFT) scheme to obtain scattering parameters of arbitrary geometry planar microstrip structures directly from the equivalent currents. These extensions imply the development of an appropriate method to fed and load the system. A new set of basis functions which improves the speed of convergence is also introduced. Besides, almost all computations are performed in the spectral domain where operators have simpler forms. Results are compared with measurements. The method is accurate and efficient from a computational point of view.