A Dual-Polarized Ultra-Wideband Fully Inverted-L Element (FILE) Array

A new dual-polarized ultra-wideband array is introduced, called the fully inverted-L element (FILE). Specifically, our dual-polarized FILE (DP-FILE) unit cell is comprised of two L-bent elements, which tightly couple to a common shorted via as well as to each other. Notably, the same shorted via is utilized to suppress the well-known common mode resonance. To lower the cost of our array, a close to optimal spacing of $0.47\lambda_{h}$ is utilized for reduced element number. Additionally, to increase its scanning capabilities, we properly (a) utilize a dual-layer superstrate, and (b) perforate both its substrate and superstrate. Our proposed element is simulated in an infinite array environment, demonstrating a 2.75 : 1 operational bandwidth (34 GHz to 94 GHz) with a maximum scan angle of 45° and orthogonal port coupling less than −10 dB for all principal E-, H- and D-planes.