Miniaturized UWB antenna with circular polarization and bandwidth reconfiguration

It is necessary to have a reconfigurable antenna for multi-function radar. The same antenna can be used for search, tracking, and imaging applications across a wide range of frequencies. The monopole antenna is suitably etched in its patch to achieve ultra-wideband (UWB) performance, while the modification of the partial ground to have an electromagnetic band gap (EBG) structure and rectangle slots improves the operational bandwidth that extends between 2.7 GHz and 12 GHz. The inclusion of a stub in the microstrip feed along with partial ground brings size miniaturization up to 63%. The perturbation of “L”-shaped slots at the corners of the rectangular patch and loading of left-hand metamaterial (LHM) into the monopole antenna realize circular polarization and also increase the gain of the antenna to 5.68 dBi. The inclusion of a filter across the feedline of the proposed antenna modifies the antenna’s frequency/bandwidth in some desirable fashion, which provides bandwidth reconfiguration. The proposed antenna uses a step feed that offers better impedance matching over the wide operating bandwidth.