Reconfigurable antennas and band gap materials

This paper describes some techniques and results for reconfiguring and tuning antennas and electromagnetic band gap materials for use in the mobile communication bands. A microstrip patch antenna operating in the 5 GHz range and tuned by liquid crystal is presented. The performance of the material has limitations for efficiency at these frequencies. Bandwidth is the limiting factor in using electromagnetic band gap materials (EBGs). This paper presents an antenna integrated with a high impedance electromagnetic bandgap surface (HIS) that can be independently tuned over two separate frequency bands. The HIS consists of a dual layer of square element based designs with varactor diodes. The tuning ranges for each band were from 700 MHz to 1200 MHz and 1700 MHz to 2600 MHz.