Modified fast inhomogeneous plane wave algorithm from low frequency to microwave frequency [computational electromagnetics]

Computational electromagnetics (CEM) is facing increasingly more complex geometries calling for more sophisticated solutions. Hence efficient fast algorithms are urgently needed and studied. Among the developed methods, the MLFMA (multi-level fast multipole algorithm) is an attractive way to solve problems with the large number of unknowns. MLFMA algorithms work well at high frequencies or low frequencies but there are low-frequency breakdown problems to be addressed. In this paper, we present a single new algorithm, MFIPWA (modified fast inhomogeneous plane wave algorithm), without the low-frequency breakdown problem of MLFMA. This method combines the extrapolation technique used in the FIPWA (fast inhomogeneous plane wave algorithm) and the evanescent-wave translation. With a single algorithm, it provides a seamless transition between high and low frequencies. Moreover, it is error controllable in a wide frequency range from static to microwave for EMC analysis. Hence, it can be used in full-band RCS computations as well as on-chip EMC simulation.