Dual band dual sense circularly polarised monopole antenna for GPS and WLAN applications

A novel circular dual band, dual sense circularly polarised (CP) monopole antenna for GPS and WLAN applications is presented. A CP bandwidth larger than 40% can be attained simply by creating rectangular slots on the circular patch of the microstrip line. By adding rectangular slots, the 3 dB axial ratio bandwidth and the −10 dB impedance bandwidth can be greatly improved. Novel and simple design of the radiating patch, large 3 dB axial ratio bandwidth and compact size of the antenna are the novel aspects of this work.