Dual-polarized dual fed vivaldi antenna for cellular base station operating at 1.7-2.7 GHz

Abstract The paper presents a novel dual polarized dual fed Vivaldi antenna structure for 1.7–2.7 GHz cellular bands. The radiating element is designed for a base station antenna array with high antenna performance criteria. One radiating element contains two parallel dual fed Vivaldi antennas for one polarization with 65 mm separation. Both Vivaldi antennas for one polarization are excited symmetrically. This means that the amplitudes for both antennas are equal, and the phase difference is zero. The orthogonal polarization is implemented in the same way. The dual polarized dual fed Vivaldi is positioned 15 mm ahead from the reflector to improve directivity. The antenna is designed for 14 dB impedance bandwidth (1.7–2.7 GHz) with better than 25 dB isolation between the antenna ports. The measured total efficiency is better than 0.625 dB (87%) and the antenna presents a flat, approximately 8.5 dB, gain in the direction of boresight over the operating bandwidth whose characteristics promote it among the best antennas in the field. Additionally, the measured cross polarization discrimination (XPD) is between 15 and 30 dB and the 3 dB beamwidth varies between 68° and 75° depending on the studied frequency

Dual-polarized 2x2 element sub-array at 15 GHz with high port isolation

Abstract This paper presents simulation results of a dual-polarized 2×2 element sub-array antenna element at 15 GHz center frequency. The basic idea is to use two waveguides stacked on in a right-angle configuration to excite the orthogonal polarizations by using radiating slots. Above the slots, 4 parasitic patches are set to a form of 2×2 element sub-array. Antenna presents -10 dB impedance bandwidth from 14.3 to 15.6 GHz with better than 68 dB isolation between the excitation ports. At the aforementioned bandwidth, the total efficiency is better than -0.7 dB (> 85%). Antenna shows very good polarization properties and difference between φ, θ components is greater than 45 dB. Also the radiation patterns and surface current distributions at 15 GHz center frequency are presented and compared