Dual Polarization Multi-Frequency Antenna Array

NASA employs various passive microwave and millimeter-wave instruments, such as spectral radiometers, for a wide range of remote sensing applications from measurements of the Earth's surface and atmosphere to cosmic background emission. These instruments such as the HIRAD (Hurricane Intensity Radiometer), SFMR (Stepped Frequency Microwave Radiometer), and LRR (Lightweight Rainfall Radiometer), provide unique data accumulation capabilities for observing sea surface wind, temperature, and rainfall and significantly enhance the understanding and predictability of hurricane intensity. These microwave instruments require extremely efficient wideband or multiband antennas. For the Phase I SBIR program Spectra Research, Inc. teamed with Scientists from the Georgia Tech Research Institute (GTRI) to apply new technological antenna advances and new antenna design tools toward solving the challenge of designing small, multi-function antennas that reduce the space, weight, and drag demand on the platform.

The results of the analysis and numerical design in the Phase I program show strong potential for an antenna array that will satisfy all design requirements of a high efficiency replacement for the Hurricane Intensity Radiometer (HIRAD) array. Multiple fragmented aperture arrays were employed in a thin antenna element to achieve exceptional gain (within 0.2 dB of the aperture limited gain) over the entire band from 4-7 GHz with a superb VSWR of < 1.5.