Ultra-Wideband Planar Dipole Array Antenna for Multifunction Phased Array Radars

Abstract

In the study, an ultra-wideband array antenna for multifunction phased array radars (MPAR) is proposed. Due to the low-profile and ultra-wideband characteristics, the planar dipole elements are utilized to form an array antenna. Their performances are enhanced by using an optimized microstrip-sector feeding structure. The array antenna is a combination of subarrays, each of which corresponds to 4 × 4 transmit/receive channels. Four subarrays are fabricated in a standard printed circuit board (PCB) process to investigate the planar dipole array antenna theoretically and experimentally. Both simulated and measured results show that the proposed array antenna achieves 87.0% impedance bandwidth (VSWR < 2.0 in the normal direction) from 1.3 GHz to 3.3 GHz, according to the specific requirements of an MPAR project. The active VSWR is less than 2.0 and 3.0 while the scan angle is −30 • ∼ 30 • and −45 • ∼ 45 • , respectively. It means that this array antenna has wide-scan capability. In general, the balanced optimization between the electrical and mechanical performances makes the proposed array antenna attractive for MPARs and other compact systems.