An Aperture-Shared Dual-Band Antenna Array Based on Upstanding Dipoles

An aperture-shared dual-band dual-polarized antenna array is developed based on upstanding dipoles for 2G/3G/4G base-station applications. The dual-band antenna array consists of one element for low-band (LB) (0.69–0.96 GHz) and four (2 × 2) elements for high-band (HB) (1.7–2.7 GHz) operation. The LB element with two crossed upstanding dipoles features a minimum cross section and thus has the least shielding to the HB elements. Four horizontal chokes are introduced on each dipole of the LB element to block the current induced by the HB elements. Slots are etched on the ground of HB elements to suppress the common-mode current induced by the LB element. The aperture-shared dual-band antenna array achieves an antenna gain of 8 dBi for the LB element and 11 dBi for a 1 × 2 HB array with stable radiation patterns.