Investigation of varactor tuned stacked patch antennas

In this paper we present an adaptive antenna based on a stacked patch radiator incorporating varactor diodes that enable the antenna to be tuned from 3 GHz to 6 GHz; an effective bandwidth of an octave. As the fundamental radiator is designed for operation at the upper frequency limit, the antenna is an electrically small radiator. The general configuration is presented as well as the design methodology is presented herein. A proof-of-concept version of the antenna was designed and developed and the measured results are also presented.