Circularly polarised aperture antenna fed by CPW and built in MCM-D technology

A new design for a circularly polarised aperture type antenna fed by a coplanar waveguide is introduced. The antenna has been built in MCM-D technology which offers an easy way to reduce the leakage to the slotline mode of the CPW. The proposed antenna has been studied both theoretically and experimentally. The results show that the antenna has both a high impedance and high circular polarisation bandwidths. It is designed to operate around 25.5 GHz. Return loss, axial ratio, and radiation patterns are presented and briefly discussed.