Novel Wideband Circularly Polarized DRA With Squint-free Radiation Characteristics

Abstract

A new single-fed circularly polarized dielectric resonator antenna (CP-DRA) without beam squint is presented. The DRA comprises of an S-shaped dielectric resonator (SDR) with a metalized edge and two rectangular dielectric resonator (RDRs) blocks. A horizontal-section is applied as an extension of the SDR, and a vertical-section is placed in parallel to the metallic edge. A vertical coaxial probe is used to excite the SDR and the vertical RDR blocks through an S-shaped metal element and a small rectangular metal strip, respectively. The two added RDRs that form an L-shaped DR improve the radiation characteristics and compensate for the beam squint errors. A wideband CP performance is achieved due to the excitation of several orthogonal modes such as TEx d11, TEy 1d1, TEz 121, TEy 112, TEx 131, and TEy 311. The experimental results demonstrate an impedance bandwidth of approximately 66:8% (3:71-7:45 GHz) and a 3-dB axial-ratio (AR) bandwidth of about 54:8% (3:72-6:53 GHz) with a stable broadside beam achieving a measured peak gain of about 4:64dBi. Furthermore, a 100% correction in beam squint value from q = 41° to q = 0° with respect to the antenna boresight is achieved.