1986, 8(1): 14-22.
Abstract:
This is the first part of our work on the dyadic Green s functions (DGF) at the souree region in circular waveguides. In this paper, a systematic and nevel approach is developed for the dyadic operation of DGF. The complete farms of the dyadie operation of DGF for circular waveguides are given. Ambiguities associated with the dyadic operation in the literature are clarified and the errors are redressed.Contrary to Kisliuk (1980, 1983), it is shown that the expansion of the longitudinal vector eigenfunctions L and the expansion ofthe transverse vector eigenfunctions M and N are not purely lognitudinal and transverse fields at the source region. In addition, it is also shown that the interchanging differential and integral operators to carry out the dyadic operation of DGF is invalid at the source region (Tai, 1973).