Calculating the impedance of patch antennas using TLM

The 3-D transmission line matrix (TLM) method is used to calculate the input impedance of patch antennas. The feed line to the antenna is simulated using a TEM line consisting of two electric and two magnetic walls. This simulation has the advantages of matching to the input microstrip and of having a known reference impedance. These two advantages makes accurate calculation of the input impedance possible. The results were compared to previously published measured data.