Design of an 8–40 GHz antenna for the wideband instrument for snow measurements (WISM)

Measurement of land surface snow remains a significant challenge in the remote sensing arena. Developing the tools needed to remotely measure Snow Water Equivalent (SWE) is an important priority. The Wideband Instrument for Snow Measurements (WISM) is being developed to address this need. WISM is an airborne instrument comprised of a dual-frequency (X- and Ku-band) Synthetic Aperture Radar (SAR) and dual-frequency (K- and Ka-band) radiometer. A unique feature of this instrument is that all measurement bands share a common antenna aperture consisting of an array-feed reflector that covers the entire bandwidth. This paper covers the design and fabrication of the wideband array feed, which is based on tightly coupled dipole arrays. Implementation using a relatively new multi-layer microfabrication process results in a small, 6×6-element, dual-linear polarized array with beamformer that operates from 8 to 40 GHz.