Study of Reconfigurable Printed Antennas for GPS Applications

This report addresses issues concerning the design, analysis and implementation of circularly polarized pattern reconfigurable printed antennas. Single and multi-layer dual band staked microstrip patches mounted on substrates/superstrates of square and octagonal shape are proposed for GPS applications. Another objective of the research described here was also to develop an accurate model for the analysis and design of switching circuits for pattern reconfigurable antennas. Modeling of all switch circuit components and accounting for the effects of the other elements like the bias lines is seen to be crucial in the design of the switch circuit, and in turn to the performance of the antenna. The design of the switching circuits is done for a single band antenna, operating at the GPS frequency of 1.575 GHz (L1) and for a dual band antenna, which operates at the 2 GPS frequencies of 1.227 GHz (L2) and L1. The single band antenna is implemented and measured. Simulated and measured results of the radiated field for this antenna are compared and found to agree fairly well.