Simple method for determining the bandwidth of rectangular patch antenna

There are two common types of analysis for the determination of bandwidth of such antennas. One approach starts with initial physical assumptions. It generally offers simple and analytical formulae. These are well suited a for physical understanding of the phenomena. Also, these are suitable for antenna computer-aided design (CAD). These methods include the transmission-line model and the cavity model (or modal expansion technique). However, these methods suffer from one major drawback. They do not consider the surface wave effects. This work suggests an improvement to the above approach. It uses the idea of transmission-line and cavity model. Determination of the complex resonant frequency leads to a simple closed form formula for radiation Q-factor. The determination of the complex resonant frequency is without using any iterative process. So, this method is useful in improving antenna CAD.