A dual element patch array antenna structure with microstrip triple stub matching

In this paper we examine a dual frequency structure suitable for mobile communications. We present a closed form solution to the triple stub section combined with the patch parameters obtained experimentally and by using a commercial simulation tool. This patch design technique allows for straightforward multiband operation without active circuitry or use of duplexers. Also presented was a method of optimizing a matching structure using genetic algorithms to solve a multivariable stub positioning problem related to impedance matching whilst at the same time limiting any radiation due to multimode excitation in the patch.