Dual frequency reconfigurable microstrip antenna using varactor diodes

Abstract

A varactor controlled electronically reconfigurable dual frequency microstrip antenna is presented. Dual frequency operation is realized by embedding an X-slot in a rectangular patch. High tuning ranges of 26.3% and 15.3% are realized for the two resonant frequencies respectively, when the bias voltage is varied from 0 to 16V. This design has an added advantage of size reduction up to 77% and 64% for the two resonant frequencies compared to standard rectangular patch. A maximum band width of 2.26% and 2.36% for the two frequencies with an operating frequency ratio varying in the range 1.156 to 1.279 is observed.