On the theory of discrete TLM Green´s functions in three-dimensional TLM

The response to a wave pulse incident on the boundary of a certain spatial domain may be represented by discrete TLM Green´s functions. On the other hand, the response to a localized electromagnetic excitation at the boundary of a certain spatial domain may be calculated directly from Maxwell´s equations and be represented by analytic TLM Green´s functions. For low frequencies and small wave numbers, the analytic TLM Green´s functions coincide with the discrete TLM Green´s functions. Applying the analytic TLM Green´s functions in the absorbing boundary condition at the boundary to the open half-space reduces the computational effort considerably when compared with the application of the discrete TLM Green´s functions