A Wideband, High-Gain, CPW-Fed, Circularly-Polarized, L-Shaped Slot Antenna Array

A single-fed, wideband, circularly-polarized (CP), 2 x 2 antenna array is presented. The array feed design is based on the sequential rotation feeding technique. A compact, wideband, CP coplanar waveguide (CPW) slot antenna is proposed as each of the array elements. It is shown that the proposed antenna performance is significantly enhanced when it is placed in the array arrangement. The impedance bandwidth of the array is 66.7% (from 1.5 GHz to 3 GHz) and its axial ratio (AR) bandwidth is 53.2% (from 1.7 GHz to 2.95 GHz) for AR < 3 dB. The antenna array has a stable radiation pattern and a gain of greater than 6 dBi over the entire CP frequency band. The overall size of the antenna array is 170 mm x 170 mm.