Dual-frequency operation of probe-fed rectangular microstrip antennas with slots: analysis and design

Dual-frequency operation of antennas is essential for many applications in communications and radar systems, and there are various techniques to achieve this operation. Most dual-band techniques used in microstrip antennas sacrifice space, cost and weight. In this thesis, a simulation and design tool for dualband microstrip antennas, with slots on the patch and a single probe feed, is presented. This approach is based on the cavity model and modal-matching technique, where the multi-port theory is employed to analyze the effect of the slots on the input impedance. The results obtained by the simulation are verified with the experimental results. In addition, for design puiposes, a genetic algorithm is developed for the optimization of coordinates and dimension of slots in order to achieve desired frequency and impedance values for dual-frequency operation