Novel Dual-Band Phase-Gradient Metascreen and Dual-Band Near-Field Meta-Steering Antennas

This article proposes first of its kind novel dual-band near-field meta-steering (DB-NFMS) antenna operating in a full duplex in the Ku-band. The antenna is developed using an entirely new dual-band phase-gradient metascreen (DB-PGM), which is synthesized to simultaneously provide the required phase gradients at the two operating frequencies. A novel characteristic of the metascreen includes a fundamental cell, which has slot-based fully metallic architectures with high structural integrity and low fabrication complexity that simultaneously allow independent radio frequency (RF) transmission in dual bands. The elimination of dielectrics reduces the cost and expands their usage to even extreme conditions, such as high-power and space applications. In addition, the DB-PGMs are polarization-insensitive and can be made out of cheap, off-the-shelf metal sheets. A prototype is made, and its dual-band beam-steering principle is verified numerically and experimentally. Irrespective of the rotation of the DB-PGMs, the measured impedance bandwidths of the antenna system at VSWR < 2 are around 400 MHz (11.57-11.97 GHz) and 1050 MHz (13.95-15.0 GHz). Within the maximum scan loss of 3 dB, the measured simultaneous beam-steering angles in the elevation plane are +/- 46 degrees and +/- 51 degrees at f(L) and f(H), respectively, with a full 360 degrees steering in the azimuth. The respective total weight and thickness of each DB-PGM are 68.8 g and 18.4 mm ( 0.72 lambda(L) ). Including feed, the overall antenna profile is only 52.8 mm ( 2.1 lambda(L) ).