Circularly polarised printed antenna miniaturised using complementary split-ring resonators and reactive pin loading

A circularly polarised printed antenna, miniaturised by utilising a combination of complementary split-ring resonators (CSRR) and reactive pin loadings, is presented. This design technique is shown to reduce the electrical size of the antenna diameter by 44% at 2.4 GHz. The antenna prototype, when radiating a right-hand circularly polarised beam, displayed 4.1 dBic of broadside realised gain with 70% radiation efficiency. Specifically, it was demonstrated that the stand-alone CSRR loading resulted in a size reduction of 30%. The addition of reactive pins enhances this factor up to 44% without causing any observable degradation in antenna performance.