Microfabricated Millimeter-Wave Antenna Arrays

This proposal addresses the need for an antenna technology platform that meets the requirements of high-performance materials, exacting dimensional tolerances, and the geometrical design freedom to enable planar antenna array technologies for frequencies greater than 90GHz. The PolyStrata fabrication technology, being developed at Nuvotronics, LCC, Blacksburg, VA., is capable of meeting or exceeding all of the requirements outlined to be a solution for these frequencies. Air-filled copper rectangular coaxial transmission lines are fabricated using a photolithographically defined layer-by-layer process. The resulting transmission lines are extremely broadband, low-dispersion, high-isolation, and low loss compared to other forms of planar transmission lines. These lines are smaller than rectangular waveguides because the transverse cross-sections of the lines are not resonant. Phase II of this work will include the design, fabrication and characterization of prototypes that will enable PolyStrata-based frequency-scanned antenna-array operating from 140-160GHz with +/-16 degree beam steering, a beamwidth of 0.5 degrees and 400MHz per beam bandwidth. An antenna array with this performance would require roughly 24cm by 24cm. This is possible using 4 sub-arrays that each are fabricated on a single wafer and then tied together to achieve the overall system performance. We will develop and deliver prototypes that will be smaller versions of this, but demonstrate all the necessary aspects of the system including the feed network, the antennas, the tiling of subarrays and the connection to the outside world. The approach will offer a high-yield, cost effective product that will meet the NASA needs.