Broadband Dual‐Beam Dual‐Polarized Antenna Array With Controllable Beam Pointing

ABSTRACT A broadband dual‐beam dual‐polarized antenna array having low sidelobe and controllable beam pointing is proposed. A crossed‐dipole antenna element with link lines is introduced to achieve excellent impedance matching, symmetrical and stable radiation pattern, low cross‐polarization level, as well as very steady gain at 1.7–2.7 GHz. Based on the element, a new staggered 2 × 2 subarray is proposed to achieve excellent sidelobe suppression over the wide operating band. Then a dual‐beam subarray, which consists of two staggered 2 × 2 subarrays and controllable metal fixtures, is designed to introduce dual‐beam performance with low sidelobe. The dual‐beam pointing can be easily controlled by tuning the metal fixtures. Finally, a dual‐beam dual‐polarized array is proposed to obtain high gain for practical application. It obtains a wide bandwidth of 45.5% (1.7–2.7 GHz) for reflection coefficient < −14 dB, and good isolation between all the ports larger than 21 dB. The array also has good dual‐beam performance, with sidelobe levels below −20 dB and beam‐pointing angles that can be varied to ±18°, ±28°, and ±38°.