Wide Angle Scanning Phased Array Antenna for Kaband Applications

This paper presents the design and analysis of a linearly polarized unit cell for phased array antenna operating in the Ka band (27.5 to 30.5 GHz) for SatCom application. The primary focus is on achieving wide bandwidth and wide beam scanning angles while maintaining low active reflection coefficient. To address the challenge of impedance matching over wide scanning angles, we propose a design methodology based on the analysis of active Voltage Standing Wave Ratio (VSWR) behavior of the radiating unit cell under periodic boundary conditions. A stacked patch Interleaved Parasitic Array Antenna (IPAA), realized without an air cavity to simplify fabrication, is optimized for beam scanning up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 70^{\circ}$</tex> off boresight in all the azimuth planes. The proposed antenna achieves a 10 % fractional bandwidth with the active reflection coefficient for an infinite array remaining below <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{- 1 3. 4} \mathbf{~ d B}$</tex> across the full bandwidth and scan range.