Rectangular Slot Array Antenna

Abstract

Slot antenna elements are quite popular for use in flat-panel arrays, due to their compactness and relatively large bandwidth. According to Babinet’s Principle, slots and dipoles are duals in performance. Therefore, a vertically placed slot is horizontally polarized and a horizontally placed slot is vertically polarized. A rectangular slot array lends itself to a broad range of applications, e.g., tactical and weather radar. Such arrays can be gimbaled to point their beam in any azimuth and elevation angle of interest. In this effort, a slot antenna element is designed in WIPL-D Pro to operate over the 7.5 - 8.5 GHz frequency range. The element is designed to resonate at 8 GHz. The slot element is used to generate a 6x12 slot array normal to the xy-plane. Separate Taylor tapers (nbar = 5) are applied to the 6-row and 12-column elements to provide 25 dB and 30 dB sidelobe level (SLL) suppression, respectively. The input impedance and pattern performance for a single slot, as well as the slot array’s radiation performance show excellent broadband performance.