Design of 2×2-Element for a Perpendicular-Corporate Feed Four-layer Parallel-Plate Pair-Slot Array Antenna

This paper presents the design of a 2×2-element subarray for a 16×16-element perpendicular-corporate feed four-layer parallel-plate pair-slot array antenna. To suppress sidelobes in the 45° plane in a conventional array antenna with the perpendicular-corporate feed, we introduce pair-slots in an additional-slot layer. They contribute to reducing higher modes in wider slots, offering the wideband design of the VSWR. In simulation results, the proposed structure can lower sidelobes around ± 55° regions in the 45° plane from -21 to dB and provide 13.0% bandwidth for VSWR ≤ 1.5.