APPLICATION OF THE IMPROVED MATRIX TYPE FDTD METHOD FOR ACTIVE ANTENNA ANALYSIS

An improved flnite-difierence time-domain (FDTD) method has been extended to analyze the antennas with complicated lumped/active networks in this paper. The improved FDTD method is based on a novel integral transform and the matrix theory. Combining the novel integral transform with Kirchhofi's circuit laws, the hybrid networks comprised of high order linear and nonlinear elements with arbitrary connection can be modeled by a stable matrix equation. An efiective model is built for linear lumped networks including internal independent sources. A wire antenna loaded with wideband match network and a two-element active patch antenna loaded with Gunn diodes are analyzed by the developed techniques. The analysis results indicate that the improved matrix-type FDTD method is not only sta- ble and accurate, but also time-saving in simulating the complicated hybrid networks.