Advanced Microwave Antenna for Airborne Soil Moisture and Salinity Mapping

The NOAA Environmental Technology Laboratory seeks to perform advanced wide-area mapping of soil moisture and salinity. This requires a large scanning antenna with aerodynamic form, narrow beamwidth, high efficiency, and dual polarization. This antenna system must provide operation at L-band (1400-1427 MHz) and C-band (6.0-6.5 GHz). This large aperture must maintain stable performance independent of changes in environment. This is important, as the test conditions require high accuracy and a high degree of calibration for the sensitivity levels that are sought. FIRST RF is proposing dual polarized microstrip antennas capable of meeting performance requirements. The design parameters and materials must be chosen carefully to achieve bandwidth, efficiency, and packaging constraints. FIRST RF is proposing separate apertures at L-band and C-band. This is due to the rigid performance requirements at each frequency. A combined frequency antenna would compromise the performance of either frequency and pose additional complexities in the radome.