Design of a 4×4 Butler Matrix for Smart Antenna System at 9.3 GHz

This research aims to develop a 4×4 Butler matrix design for a smart radar antenna operating at 9.3 GHz for military surveillance radar applications. The goal is to create an effective and efficient phase-shifting Butler matrix that can dynamically alter the beam of the antenna array, enabling 180° beamforming. The substrate material utilized is Roger RT Duroid 3010. Simulated results demonstrate that the 4×4 matrix had a return loss of < -19 dB at edge ports and < -15 dB at central ports, with phase deviations of <6°.