Wideband Circularly Polarized Trapezoidal Dielectric Resonator Antenna

A wideband circularly polarized (CP) trapezoidal dielectric resonator antenna (DRA) is investigated in this letter. The DRA is simply excited by a single 45° inclined slot fed by a microstrip feed line. It is found that the 3-dB axial ratio (AR) bandwidth of the proposed antenna can be as wide as 21.5%. The antenna gain varies between 5.28 and 8.40 dBi across the antenna passband (3.11-3.86 GHz). This letter also presents a modified trapezoidal DRA that has a notch at its top. The modified version improves the impedance match, as the AR and gain remain almost unchanged. The reflection coefficient, AR, radiation pattern, and antenna gain of each proposed configuration are studied, and reasonable agreement between the measured and simulated results is observed.