A Novel Reconfigurable Hexagonal Slot Loaded Microstrip Antenna

The design of a compact, varactor controlled, electronically reconfigurable dual frequency microstrip antenna is presented in this paper. Dual frequency operation is realized by embedding a hexagonal slot with extended slot arms within a square patch. Varactor diodes integrated with the slot arms are used to tune the operating frequencies considerably, by applying reverse bias voltage. Tuning ranges of 21% and 12.9% are realized for the two resonant frequencies respectively, when the bias voltage is varied from 0 to -30V. This design has an added advantage of size reduction up to 80% and 70.18% for the two resonant frequencies compared to standard rectangular patch. A maximum band width of 6.2176% and 10.4255% for the two frequencies with an operating frequency ratio varying in the range 1.0645 to 1.2180 is observed.