A wideband coplanar waveguide-fed circularly polarised antenna

A wideband coplanar waveguide (CPW)-fed circularly polarised antenna is presented. It contains two loops arranged in an unusual way. One unique feature is that the positive signal line of the CPW is split into one vertical and one horizontal arm after a simple match. Another large surrounding open ring is used to suppress the surface wave. The antenna has more than 20% 10 dB return loss and 3 dB axial ratio bandwidth.