Omnidirectional Circularly Polarized Dielectric Resonator Antenna for 5.2-GHz WLAN Applications

The rectangular dielectric resonator antenna (RDRA) is presented to generate linearly polarized (LP) with omnidirectional radiation patterns. The proposed omnidirectional LP DRA is fed centrally by a coaxial probe and offers an impedance bandwidth of 130 MHz between 5.15 and 5.35 GHz for vertical bar S-11 vertical bar < -10 dB, which can be useful for 5.2-GHz WLAN applications. It is noted that by introducing several inclined slits to the diagonal and sidewalls of the RDR and also deducting a rectangular part of the top wall of the LP RDRA, degeneracy mode is excited to generate the circularly polarized (CP) fields. The proposed omnidirectional CP DRA with axial-ratio (AR) bandwidth of 210 MHz was designed for WLAN (5.15-5.35 GHz) applications. A parametric study is presented. The proposed CP DRA is built, and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained.