All-Metal, High-Efficiency and Wide-Scanning Phased Array Antenna with Sparse Architecture for 6G High-Integration RF Front-End

This paper proposes an all-metal and periodically-sparse phased array antenna, which operates from 66 GHz to 76 GHz with high-efficiency and wide-scanning performance. The rectangular waveguide is modified with the double-ridge to extend the single
$\mathbf{TE}_{10}$
mode bandwidth at first. The tapered slot antenna acts as the unit cell and is fed by the ridge waveguide. The adjacent unit cells are connected to enhance the electromagnetic-field continuity of the antenna aperture, so that the bandwidth of the antenna element is wider. The 4-element subarray is excited by the low-loss power divider and the Teflon phase shifters. After the design procedure by the invasive weed optimization and the iterative convex optimization algorithms, the optimal array achieves the 75% channel reduction and the wide-scanning range over
$\pm \mathbf{60}^{\circ}$
without the grating lobes. Moreover, compared with the antenna based on the organic materials, the proposed all-metal antenna achieves the remarkable thermal dissipation performance.