Full-wave analysis of guiding structures using a 2-D array of 3-D TLM nodes

A TLM approach to the full-wave analysis of guided wave structures is introduced. Instead of real pulses as in the conventional TLM method, complex pulses are used. Therefore a nonreciprocal phase shift in the z-direction can be introduced and used to connect the z arms in a 3-D node directly. As a result, the 3-D array of 3-D nodes, normally required in the TLM method to calculate the propagation and attenuation constant, is reduced to only one mesh unit in the z direction (a 2-D array of 3-D nodes). The propagation constant is determined by choosing a value and then calculating the frequency at which this value is valid from the Fourier transform of the impulse response. Losses are found by computing the exponential decay of time harmonic solutions at the eigenfrequencies of the structure