High-Gain Wide-Angle Scanning Array Using Slot-Based Patch Antenna for Ku-Band

High-gain wide-angle scanning antennas are vital for emerging Ku-band satellite communication systems supporting mobile, IoT, and UAV platforms. However, achieving compactness, circular polarization, and stable gain over a wide scanning range remains a key design c1hallenge. This paper presents a Slot-Based Microstrip Patch Antenna (SBMPA) array optimized for high-gain, reconfigurable circularly polarized (CP) operation in the Ku-band (12.85–13.05 GHz). Each SBMPA element integrates a slotted circular patch nested inside a concentric annular ring operating in the TM<inf>11</inf> (axial) and TM<inf>21</inf> (conical) modes, respectively. With a quadrature-feed network, the antenna generates a tilted CP beam (θ = 35°) with a gain of 6.8 dBic and can switch between right-hand circular polarization (RHCP), left-hand circular polarization (LHCP), and linear polarization (LP) modes. A four-element linear SBMPA array, controlled through a phase-shift network, achieves beam steering up to −47° with −3 dB coverage extending to −60°, while maintaining a stable gain of 10.2 ± 1 dBic and low sidelobe levels (–9 dB). The proposed array offers a compact, polarization-agile solution with robust performance, making it suitable for low-profile satellite terminals and near-horizon communication in next-generation Ku-band applications.