  We proposed a simple and efficient modular single-source surface integral
equation (SS-SIE) formulation for electromagnetic analysis of arbitrarily
connected penetrable and perfectly electrical conductor (PEC) objects in
two-dimensional space. In this formulation, a modular equivalent model for each
penetrable object consisting of the composite structure is first independently
constructed through replacing it by the background medium, no matter whether it
is surrounded by the background medium, other media, or partially connected
objects, and enforcing an equivalent electric current density on the boundary
to remain fields in the exterior region unchanged. Then, by combining all the
modular models and any possible PEC objects together, an equivalent model for
the composite structure can be derived. The troublesome junction handling
techniques are not needed and non-conformal meshes are intrinsically supported.
The proposed SS-SIE formulation is simple to implement, efficient, and
flexible, which shows significant performance improvement in terms of CPU time
compared with the original SS-SIE formulation and the
Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation. Several numerical
examples including the coated dielectric cuboid, the large lossy objects, the
planar layered dielectric structure, and the partially connected dielectric and
PEC structure are carried out to validate its accuracy, efficiency and
robustness.
