Predicting the current on wires with TLM using self-consistent and non self-consistent approaches [EMC analysis]

The transmission line matrix (TLM) method has proved to be an accurate and popular technique for solving electromagnetic compatibility (EMC) problems. A common EMC problem is to predict the current on thin wires. Recently special models have been introduced that enable thin wires to be considered in the TLM simulation. These are mostly models where there is coupling from the electromagnetic field to the wire and vice-versa, thereby allowing the wires to modify the fields. However if the coupling was only one way (i.e. from the electromagnetic fields to the wire), and the scattering due to the wires ignored, a large number of possible cabling layouts could be considered in a single TLM calculation. This is termed a non self-consistent approach. This paper discusses the implementation of both self and non self-consistent wire models in TLM, and compares the results obtained using both approaches. It is shown that while there are some differences in the results, the non self-consistent model appears on initial investigation to be accurate enough for EMC evaluation of designs.