Beam-Steering Metasurface Antenna for Lunar Soil Moisture Sensing

A phase II effort will build on the success of the phase I effort and move from demonstrating a passive antenna to an electronically steered 2D dynamically metasurface aperture (DMA). By appropriately tuning each element on the metasurface, using metasurface-specific algorithms, we will demonstrate a high gain electronically steered beam with fast switching speeds. This approach lends itself to minimize total power consumption, and by association, cooling requirements. A DMA will uses inexpensive components (e.g., varactors and DACs at a few $ each) and unlike an AESA, the DMA does not require phase shifters or densely packed transmission/receivernbsp;modules. As a result, production DMA antennas are expected to have a bill of materials (BOM) of around $100k per square meter, or less, making it possible to build large, high-performancemdash;but relatively inexpensivemdash;apertures. Further, in exploring the DMA for very large aperture systems, the Duke team has discovered a variation of the metasurface architecture that minimizes the number of components needed to achieve the requisite beam forming and beam steering performance, further reducing antenna costs. Ultimately, the DMA design maintains the advantages of a sparse phased array, but with the extreme field of regard associated with advanced active electronic scanned arrays (AESA) systems.The antenna platform we envision here will harness commercial printed circuit board (PCB) manufacturing techniques to produce the top metasurface layer. A multilayer waveguide feed will be fabricated with additive 3D printing methods and uses a conductive polymer that can be electroplated for low loss. This, advantageously, supports a very lightweight antenna and great flexibility in its geometry, traits that reduce launch costs in a satellite environment.