Time Domain Integral Equation solver for composite scatterers using a separable expansion for convolution with the retarded potential

Time Domain Integral Equations (TDIEs) have been plagued by instabilities since their inception. The computational community has invested significant time and effort in attempts to remedy the issue to varying success. Recent work on exact integration methods has shed further light on the importance of accurate matrix evaluation to TDIE stability, but their extension to higher order geometries is highly nontrivial. This was largely the inspiration for a method which relied on a separable approximation in space and time of the convolution with the retarded potential. This method was shown to produce late time stable results on a variety of perfectly electrically conducting objects. This work presents the extension of this method to composite scatterers.