Millimeter-Wave Wide-Angle Scanning Phased Array Antenna Based on Heterogeneous Beam Elements

By imitating the element-inclined beam distribution of a curved surface conformal (CSC) phased array antenna (PAA), a pseudo-CSC (PCSC) PAA realizes wide-angle scanning while maintaining a planar low profile. Inspired by the PCSC PAA, this communication proposes a PAA based on heterogeneous beam elements (HBEs) to realize wide-angle scanning. Using HBEs introduces a new design degrees of freedom (DoFs), namely the element beam shape, to PAA. By optimizing HBEs and their arrangement, the effective aperture of a PAA can be increased at large scanning angles, and thus the scanning range can be improved. To verify the idea, first, a wide-beam
$1\times4$
-element subarray is developed. Then, a standard
$4\times4$
-element PAA is implemented using four uniform
$1\times4$
-element subarrays, achieving a
$>\pm 60^{\circ }$
3-dB gain variation scanning range. At last, based on the standard PAA, by adjusting its structure to tailor four subarrays’ beam inclinations, a
$4\times4$
-element HBE PAA is designed. It further improves the scanning range to
$>\pm 70^{\circ }$
at an average cost of ~1.5 dBi broadside scanning gain within the 5G mmWave band (24.25–29.5 GHz, 19.5%). To the authors’ best knowledge, compared with the former planar mmWave PAAs, the proposed design shows the widest scanning range in a wide bandwidth.