Review of Wide-Angle Scanning Phased Arrays Based on Element-Level Beamforming Method

The phased array antenna with wide beam coverage can increase the signal coverage area, and plays a crucial role in the wireless system. To realize phased arrays with wide scanning angle, this paper presents two strategies based on the element-level beamforming method. By dynamically reconfiguring radiation patterns of antenna elements through phase control, the designed phased arrays deliver precise beam steering, minimizing structural complexity and active losses. The first array employs a TM <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{T M}_{\text{2 2}}$</tex>-mode loop antenna spatially surrounding a TM <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">${ }_{10}$</tex>-mode patch antenna, and its beam coverage reaches <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 72^{\circ}$</tex> in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4.4-5 \text{GHz}$</tex>. The second array utilizes a linearly open-ended tapered radiating slot and TM01-mode symmetrical patches, achieving <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 55^{\circ}$</tex> beam coverage in the boresight direction and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 65^{\circ}$</tex> beam coverage in the endfire direction in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{2 4 - 2 8 ~ G H z}$</tex>.