Planar 2-D Beam Steering Antenna Using Liquid Metal Parasitics

Abstract

We demonstrate a single-feed planar antenna capable of 2-D beam-steering using pumped liquid metal (LM) parasitics. Instead of relying on phase shifters for beam-steering, the proposed antenna employs LM plugs acting as parasitic elements to achieve up to ±48° steering in the H-plane and ±54° steering in the E-plane. The antenna can also steer in diagonal and OFF-diagonal planes using a combination of the E and H plane steering techniques. Simultaneously, the antenna maintains a 2:1 VSWR for all the states. By creating a composite realized gain plot for all these states, it is seen that the antenna can cover as much as 23% of the spherical area with at least 5 dBi of realized gain, compared to 4.5% in the absence of LM parasitic elements for beam-steering. We also quantify the pattern diversity (PD) and illustrate that the antenna achieves a greater PD than an electrically scanned $2 \times 2$ phased array occupying an equivalent aperture ( $0.55\lambda _{0} \times 0.66\lambda _{0}$ ).