A High-gain Low-sidelobe Dual-polarized Broadband Array Antenna

Abstract

In this paper, we present a dual-polarized broadband low side lobe array designed for operation in the Ku-band. The antenna array operates within the frequency range of 14.0 GHz to 15.2 GHz, covering a bandwidth of over 8%. To realize this wide operational frequency, we have selected broadband microstrip antenna elements as the units of the array. In order to fulfill the demanding criteria of broadband performance and low sidelobe characteristics, we introduce a broadband low-sidelobe feeding network based on a directional coupler design. This feeding network ensures connectivity with the antenna units, resulting in a voltage standing wave ratio (VSWR) < 2 within the 14.0 GHz to 15.2 GHz frequency range. Furthermore, our antenna array achieves an array gain exceeding 21 dBi and keeps array sidelobes below -20 dB across the entire operating frequency band. Our research breakthrough addresses the critical design challenge of creating large-scale array antennas that combine broadband capabilities with high gain and minimal sidelobe interference.