Hybrid Transmission Line Matrix — Multipole Expansion (TLMME) Method

The Transmission Line Matrix (TLM) method, as considered here, is a numerical time-domain technique which has been used since its introduction by Johns and Beurle [1] in 1971 to solve various problems in electromagnetic engineering. In TLM the field is discretized in space and time and modeled by wave pulses propagating and being scattered in a mesh of transmission lines. When radiating electromagnetic structures are modeled the appropriate radiating boundary conditions at the boundary of the computational domain need to be included in the computation. In the literature methods to realize absorbing boundary conditions (ABCs) are discussed [2], [3]. However, these methods give only approximate solutions of the problem.