Compact Broadband Filtering Differential Dielectric Resonator Antenna for Dual-Polarized Applications

A dual-polarized compact broadband filtering differential dielectric resonator antenna (DDRA) is proposed. For each polarization, an electric dipole is loaded on the symmetric plane of the dielectric resonator (DR) and utilized to excite the DR, which further stimulates an upper dielectric patch (DP). Three differential resonances, the half-wavelength resonance of the dipole, TE111y (TE111x) mode of the DR, and quasi-TE121z (quasi-TE211z) mode of the DP, are introduced into the operating band, respectively. The DP also improves the coupling degree of these resonances to obtain a broadband and flat-gain performance with high radiation efficiency. Furthermore, two radiation nulls at band edges are obtained without extra filtering circuits. The orthogonality of the degenerate modes enables dual-polarization for the design. A prototype is designed and implemented for verification.