Fast Computation of the Dyadic Green's Function for Layered Media via Interpolation

Abstract

The use of a dyadic layered-medium Green's function as the kernel in a method of moments (MoM) modeling problem greatly reduces the complexity of modeling a stratified medium. Compared to the free-space Green's function, there is an additional cost of having to compute a semi-infinite Sommerfeld integral for each call to calculate the dyadic layered-medium Green's function. This letter discusses a method to tabulate and interpolate the Green's function as a method of reducing the impedance matrix filling time. This method can be used in conjunction with existing methods for increasing the computational speed of the Green's functions.

Pulsed EM Field, Close-Range Signal Transfer in Layered Configurations—A Time-Domain Analysis

“…This procedure requires the ray functions to be independent of . However, from (18), (30), and (31) (38) is the instantaneous response of the reflection coefficient (an -independent quantity) and…”

“…Nonetheless, the nonzero conductivity in results in an -dependence of [see (18), (30) and (31)] that needs to be removed before invoking the Cagniard-DeHoop formalism. The strategy adopted to this end is reminiscent of that in [38], with the conceptual extension of carefully investigating its applicability conditions.…”

The Weighted Averages Algorithm Revisited

“…Nothing prevents us from applying again a WA procedure to the first-order WA estimations and to generalize (14) as a multilevel procedure, defined by the expression (16) Obviously, -successive applications of (16) will produce a single last result which should be considered as the best estimation of the infinite integral that can be extracted from the sequence . The critical point here is how to select the weights when using (16) at successive levels .…”

“…The recursive application of WA according to (16) can be viewed as a triangular process, transforming the original sequence into a new sequence according to the scheme:…”

“…These algorithms are customarily included in existing software tools, either for direct use or as a benchmark to evaluate the accuracy of faster but approximate methods like the complex image formulations [10]- [15]. Today, the WA-based algorithm remains as popular as ever, as witnessed by several recently published papers [16]- [18].…”