Wideband Triple-Resonant Sectorial Dipole Antenna with Multi-stub Loading

A novel three-halves wavelength, wideband triple-resonant sectorial dipole antenna is presented. At first, the centered angles of the principal dipole and the homologous available resonance modes are synthesized based on three-halves wavelength prototype electric dipole. Then, three transversal electric (TE) modes are simultaneously excited by symmetrically introducing multiple tuning stubs on the periphery of a sectorial radiator to achieve a wideband, multi-resonant radiation characteristic. Finally, prototype mounted above a circular metallic planar reflector is yielded and validated. Verified by experiment, the proposed antenna exhibits a wide bandwidth with its impedance bandwidth over 68.2% (i.e., 1.54-3.13 GHz). Simultaneously, less frequency-dispersive radiation patterns with gain variation < 1.1 dB, good polarization purity of cross polarization level < -22 dB, and high boresight gain up to 7.2 dBi can be obtained within the available radiation bandwidth.