Sub-array based Tile Array Antenna for Beam Forming and Multi-Beam Radar Applications in X-Band

This work asserts the design of a sub-array based tile antenna array for a CW RADAR in X Band. The CW target detection requires beam forming ability with adaptable beam scan area / multiple beam formation. This is achieved by controlling the source of signaling at the tile /sub-array/ element level of a large aperture. The sub-array presented in this work comprises multi-layered uniform-fed antenna elements arranged in a 4 × 4 planar structure, operating over a broad bandwidth of 400 MHz ($10.1-10.5 {GHz}$). The proposed sub-array configuration achieved an impedance matching better than $-10 \mathbf{d B}$, gain of $17.9 \mathbf{d B i}, 3 \mathbf{d B}$ beamwidth of $22.1 \mathbf{d e g}$, and side lobe level $\lt -13 \mathbf{d B}$ over the operating band. The sub-array beam steering performance is demonstrated up to 45°. The sub-array is extended to an 8 × 8 tile array aperture with beam switching configuration S1, S2, S3 & S4, demonstrating four beams from a single array aperture. The sub-array and tile antenna array are fabricated, and the simulated performance is validated through measurement.