Phased array antenna design considerations for large aperture microwave radiometer earth observations

An effort to assess the potential and limitations of phased array antenna microwave/mmW precision radiometry and to identify novel designs for achieving satisfactory performance with acceptable complexity and weight has been completed. The intended function of the radiometer would be space-based geophysical sensing. Principal architectures under consideration for this effort included: RF amplifiers (low-noise amplifiers or LNAs) located at the array level, each associated with a unique phase shifter; space feed lens and corporate network constrained feed combiners; and array fed reflectors as well as stand-alone arrays. Reasonably detailed expressions for models of array lens and corporate network combiner gains have been developed. These models were used in the development of system models for use in quantitatively assessing the impact of component limitations on sensitivity and accuracy, and the limitations of components necessary to achieve specified sensitivities and accuracies. Components under consideration included LNAs, phase shifters, radiating elements, and combiners.<>