A novel feed system for soil moisture spaceborne radar: dual-frequency dual-polarized stacked patch microstrip array

This paper describes the development and performance of a dual-frequency and dual-linear polarization microstrip antenna to be used in a synthetic aperture radar (SAR) for remote-sensing applications. The synthetic aperture radar (SAR) UHF/VHF design is used to deliver data for estimation of soil moisture. Two operating frequencies of 137.5 MHz and 435 MHz have been chosen to separate the effects of vegetation and soil and polarimetry at each frequency is needed to sufficiently characterize vegetation and soil. The planned parabolic reflector antenna has two different antenna widths of 30 m by 2.8 m at UHF and 30 m by 11 m at VHF by subilluminating a 30 m parabolic reflector antenna with a dual-frequency stacked microstrip array feed.