Axial ratio enhanced wideband circularly polarized aperture antenna with corner-truncated AMC reflector

In this paper, a corner-truncated artificial magnetic conductor (CT-AMC) reflector backed octagonal-shaped aperture (OSA) antenna is proposed for wideband circularly polarized application. By introducing a CT-AMC reflector, a bidirectional radiation of OSA antenna is changed to unidirectional radiation, and the axial ratio bandwidth and gain increased obviously. Moreover, electromagnetic simulations and measurements of antenna performances agree well over the whole frequency range of interest. The measured results show that 3 dB axial ratio (AR) bandwidth increase to 31.6 % with impedance bandwidth of 38.3% for |S₁₁|<; -10, and the gain of 8.0 dBi is achieved at the frequency of 5.0 GHz.