Numerical analysis of simple TEM conical-like antennas using mode matching in time domain

The paper describes a numerical technique for calculating transient radiation fields (both near and far zone) of simple conical antennas such as bi-conical, disc-conical, TEM-horn, bow-tie antennas, etc. The method is based on applying mode matching technique to the junction of two conical waveguides one of which is the free space. The problem is considered in time domain, the antenna is excited with a TEM-wave, and waveforms of the radiated spherical harmonics are determined using FDTD time marching for the uncoupled mode channels with matching condition at the junction.