Contents I. Introduction
Recent years have seen many designs of millimeter wave phased arrays and their applications in 5G communication systems [1], [2], [3], [4], [5], [6]. Since the current licensed 5G new radio frequency range 2 (NR FR2) spreads across a wide spectrum from 24.25 to 48.2 GHz (n257 to n262) [Fig. 1(a)], demands of a single, multi-standard array which could operate at all these bands have increased significantly. Dual-band solutions have been demonstrated in [7], [8], but the lack of dedicated dual-band beamformer chips has limited its aperture size. Work in [9], [10], [11] presented ultra-wideband phased array design from 16-52 GHz, but these arrays employ printed Vivaldi antennas and use several PCBs to form a two-dimensional (2D) array, which makes them expensive, bulky and difficult to assemble.
