Delta-gap port model for surface-volume-surface electric field integral equation
This thesis presents a delta-gap source model for recently introduced Surface- Volume-Surface Electric Field Integral Equation (SVS-EFIE). The SVS-EFIE is a class of single-source integral equations (SSIEs), which is obtained from the combination of the volumetric equivalence principle with the conventional single-source eld representation. The classical delta-gap port model is extended for use in SVS-EFIE for the solution of antenna radiation problem, extraction of network parameters in 3D interconnects, and characterization of the microwave circuits. The delta-gap source model for SVS-EFIE is derived from the conventional delta-gap model used in the classical surface EFIE. However, due to single-source nature of the SVS-EFIE equation, the net current in the port is determined through integration of the volumetric conductivity current density in the port cross-section. The proposed delta-gap driven SVS-EFIE is discretized using Method of Moments (MoM) with Rao-Wilton-Glisson (RWG) basis functions representing the surface current and piece-wise basis functions in the tetrahedrons discretizing the current in the conductor volume. The proposed model of port excitation in SVS-EFIE is validated through the studies of the current distribution and the frequency-dependent input impedance of a dipole antenna. Extracted input impedance values obtained with SVS-EFIE are compared against those in the classical EFIE as well as experimental values. Convergence analysis of the computed values of the input impedance with progressively increasing densities of the MoM meshes is performed. Input impedance extracted with delta-gap excited SVS-EFIE shows stable values upon mesh refi nement unlike those in the standard surface EFIE driven by a delta-gap port. This mesh stability of the extracted network parameters upon delta-gap excitation as well as the ability of the SVS-EFIE to rigorously compute volumetric eld behaviour and, hence, loss behaviour in the presence of skin-, corner- and proximity-effects makes it an attractive alternative to the classical EFIE solutions for antenna analysis and circuit characterization.
(Computational Electromagnetics, Integral Equation, SVS-EFIE, Antenna, Delta-Gap)