Compact Cooperative-Mode Differential Circularly Polarized Dielectric Resonator Antenna

A compact broadband cooperative-mode filtering differentially inserted-fed circular-polarized dielectric resonator (DR) antenna (DRA) is proposed. The dominant mode HEM111 of the circular DR is differentially stimulated by a pair of embedded bifurcated arc metal strips which generate two extra resonances. A cross slot etched on the reflecting ground and the cuttings on the DR are implemented to improve the axial ratio (AR), and introduce one more resonance to broaden the bandwidth for circular polarization in differential-end systems. An elliptic arc microstrip line is employed for the applications in single-end systems and provides more hybrid modes, resulting in a wider operation band. Two radiation nulls are also achieved at both edges of the band for high frequency selectivity. The proposed design method realizes broadband and filtering performance for circular-polarized DRAs without increasing the size.