This work focuses on efficient numerical techniques for solving electromagnetic wave
scattering problems. The research is focused on three main areas: scattering from perfect
electric conductors, 2D dielectric scatterers and 3D dielectric scattering objects. The
problem of fields scattered from perfect electric conductors is formulated using the Electric
Field Integral Equation. The Coupled Field Integral Equation is used when a 2D homogeneous
dielectric object is considered. The Combined Field Integral Equation describes the
problem of scattering from 3D homogeneous dielectric objects. Discretising the Integral
Equation Formulation using the Method of Moments creates the matrix equation that is
to be solved. Due to the large number of discretisations necessary the resulting matrices
are of significant size and therefore the matrix equations cannot be solved by direct inversion
and iterative methods are employed instead. Various iterative techniques for solving
the matrix equation are presented including stationary methods such as the ”forwardbackward”
technique, as well its matrix-block version. A novel iterative solver referred to
as Buffered Block Forward Backward (BBFB) method is then described and investigated.
It is shown that the incorporation of buffer regions dampens spurious diffraction effects
and increases the computational efficiency of the algorithm. The BBFB is applied to both
perfect electric conductors and homogeneous dielectric objects. The convergence of the
BBFB method is compared to that of other techniques and it is shown that, depending on
the grouping and buffering used, it can be more effective than classical methods based on
Krylov subspaces for example. A possible application of the BBFB, namely the design of
2D dielectric photonic band-gap TeraHertz waveguides is investigated.
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Metadata
Item Type:
Thesis (PhD)
Date of Award:
11 February 2010
Refereed:
No
Supervisor(s):
Brennan, Conor
Uncontrolled Keywords:
EM wave scattering; stationary methods; buffered block forward backward; successive symmetric over relaxation; integral equation; method of moments