FINITE DIFFERENCE TIME DOMAIN SUBCELL METHOD FOR FREQUENCY-DEPENDENT MEDIA IN COMPUTATIONAL ELECTROMAGNETICS

Abstract

The Finite-Difference Time-Domain (FDTD) is a widely used method in computational electromagnetics to model the electromagnetic wave propagation for a variety of applications ranging from radar technology through microwave radios to bioelectromagnetism. The FDTD method has a simple equational structure, making it easy to implement with accurate computational results. The accuracy of the FDTD method depends on the space step size, which in turn, is constrained by the size of the smallest geometrical feature in the FDTD space. For fine geometrical features, the FDTD method requires extreme computational memory and CPU time due to the small space step size and small time step required to satisfy the Courant-Friedrichs-Lewy (CFL) condition. The subcell method is used to remove the need to reduce the space step size, and thus permits the computational burden to be reduced without loss of accuracy. Therefore, this thesis develops a subcell model for the frequency-dependent thin layer embedded in frequency-dependent media. Both the thin layer and surrounding media are presented using a one-pole Debye model. The proposed model is offered as an addition to the model for Debye media in [1], and an extension to the frequency-dependent Debye media of the Maloney model [2] in the case of dielectric or lossy thin layers. The proposed model is thus compared with analytical solutions in the frequency domain, and with numerical references in the time domain. This thesis proposes a new method for computing the reflection and transmission of plane waves using the proposed subcell model.

Date of Award	1 Aug 2021
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Laith Danoon (Supervisor) & Fumie Costen (Supervisor)