Incorporation of feed-network modeling into the time-domain finite element analysis of antennas

In this paper, a numerical approach to incorporating a feed-network modeling into the TDFEM analysis of antennas is described. In this approach, a feed network is considered as a multi-port linear passive system, which is connected to the source and the antennas solely through several ports. Based on an appropriate numerical method, a simplified circuit model for this system can be established and analyzed (or optimized) using a circuit simulation method. Based on such analysis, a reduced-order model can be developed, which captures the important characteristics of the original feed network. This reduced-order model, in the form of a pre-calculated reduced-order admittance matrix, is then hybridized with the TDFEM through a feed port and a time convolution to provide excitation to the antennas as well as to receive the reflected fields from the antennas and feed back into the feed network. In this paper, the formulation for this proposed method is given in the following section. Two simple radiation examples are presented to validate this formulation.