Implementation of Beam Steering/ Beam Scanning Based Semi-Flexible Antenna Array System Using the Modified Butler Matrix Topology

The proposed work validates 4 × 4 modified butler matrix feeding network to get the beam steering capability in the slotted antenna array formation. The proposed array system consists of 4 patches with vertical slotted lines in decreasing order to form more capacitance, excited with the modified butler matrix feeding network for getting better directivity. Here, each input feedline of the butler matrix provides the 50-matched transmission line, obtaining better impedance matching and good impedance bandwidth. The proposed work achieves an impedance bandwidth (S11 > -10 dB) of 8.9–11.2 GHz (2.3 GHz, 22.89%), has a realized gain of 9.1 dBi, and four consistent orthogonal beams, which are provided the main beam-steering direction of radiation beams at precise angles such as ±29° and ±38°, respectively. The isolation between each input port of the modified butler matrix shows higher than 15 dB, providing the advancement of military and RADAR communication technologies applications.