A Broadband Dual-Polarized Four-leaf Clover Antenna for Base Stations

A broadband dual-polarized four-leaf clover antenna is proposed for 2G/3G/LTE base stations. The four-leaf clover antenna consists of two perpendicularly crossed bow-tie dipoles. Each bow-tie dipole is excited by a microstrip stub that is directly fed by a coaxial line, making the four-leaf clover antenna full planar. It is shown that the four-leaf clover planar antenna has a bandwidth of 45% (1.7-2.7 GHz) for return loss >15 dB with an isolation of higher than 30 dB. The dual-polarized antenna has a half-power beamwidth (HPBW) of around 65 degrees and an average gain of 8.5 dBi for slant +/- 45 degrees polarizations. An 8-element four-leaf clover antenna array is developed.