Source reconstruction with superresolution using TLM time reversal

Direct field-based synthesis of electromagnetic structures from specifications (as opposed to recurring analysis with optimization) remains a frontier in computational electromagnetics. The fundamental issues boil down to the reconstruction or imaging of direct and/or induced field sources with superresolution, and the control of non-unicity of the inverse problem. In this paper we describe three source reconstruction approaches that leverage the ability of time and space discrete Transmission Line Matrix (TLM) networks to transmit near-field information to the far-field and back, provided that the spectrum is not restricted to wavelengths large compared to the cell size. This seemingly required bandwidth limitation has frustrated previously reported attempts at structure synthesis through time reversal. We show that mesh resolution can be achieved if the full TLM bandwidth is used.