Analysis of a CPW-fed slot ring antenna

A coplanar waveguide (CPW)-fed slot ring antenna is analysed by using a spectral domain moment method. The equivalent magnetic current on the slot is expressed by a set of global bases. Travelling wave type of bases are used on the CPW with linear basis functions near the junction of slot ring and CPW. Results of IE3D and experiment are compared to verify this approach. Other feed lines using microstrip and stripline are also studied. It is concluded that the CPW feed has a better performance than the other two.