RESHAPE: A Liquid Metal-Based Reshapable Aperture for Compound Frequency, Pattern, and Polarization Reconfiguration

Abstract

We demonstrate a single-feed planar antenna capable of independently reconfiguring its operating frequency, radiation pattern, and polarization using stretchable, encapsulated liquid-metal (LM) parasitic elements. The LM is contained within elastomeric fibers that can be mechanically translated, stretched, or relaxed to alter the position or length of each conducting element on a 2-D surface, physically reshaping the metal on the antenna aperture. This eliminates several practical challenges associated with fluidic actuation of LM and makes the actuation scheme much faster and more reliable than other recent approaches. Using this scheme, the reshapable aperture (RESHAPE) design supports continuously reconfigurable operating frequencies from 2.45 to 6.5 GHz while supporting either linear $\hat {y}$ - or $\hat {\textrm {z}}$ -polarizations. At the same time, the radiation pattern can also be reconfigured in all planes, over a continuous range, to a maximum of ±45° away from the broadside direction for most frequencies. For all these possible states, the antenna maintains a 2:1 VSWR and a total efficiency of >60%. We explain the operation of the design at several frequencies, analyze the coverage area, and present measurements of a fabricated prototype.