Numerical aspects in time domain modelling of arbitrarily curved thin wire antennas

This paper deals with the numerical modelling of arbitrarily shaped curved antennas by marching on in time (MoT) technique. This time domain version of the method of moments (MoM) is particularly suitable for transient analysis and, in this respect, is more efficient than the frequency domain approach. It produces an iterative algorithm which can be easily computed without inversion of matrices. Actually, in spite of its advantages it is not widely used to analyse structures with arbitrary shape because it involves stability and numerical convergence problem. This work presents a detailed analysis of such problems and provides general rules to characterize thin wire structures. In particular dipole, loop and helical antennas are studied, because they are involved in electromagnetic compatibility (EMC) problems of coupling between the radiation of hand set antennas and human head.