Characteristic Variables Patching Conditions in Multidomain Pseudospectral Time Domain

In this letter, a uniform representation for patching conditions using characteristic variables (CVs) is proposed to treat distinct types of interfaces in multidomain pseudospectral time domain (MPSTD) algorithm. Patching conditions using CVs implicitly consider wave propagation property and physical boundary conditions. Instead of direct use of physical boundary conditions, it is more accurate and stable to match boundary conditions at the interfaces separating two subdomains of different materials. The good performance of the scheme is demonstrated by numerical examples.