Inflatable parabolic torus reflector antenna for space-borne applications: concept, design and analysis

There are many scientific and observational missions that necessitate the application of space-borne satellites with large antennas. The soil moisture radiation mission is a recently proposed space-borne passive microwave system complementary to the existing Earth Observation System. The concept requires an antenna with multi-beam, high beam efficiency, and dual polarization capability operating at L- and S-Band. To achieve both the large reflector size (about 25 meters) and the multi-beam pattern at the operational frequencies, an innovative multi-beam reflector antenna design was needed. Recent advances in inflatable antenna technology have been proposed to overcome the launch vehicle size and weight restrictions. This paper presents a novel offset parabolic torus reflector antenna design that produces the desired multi-beam pattern and is compatible with the inflatable antenna technology. Using the system requirements of this mission as an example, the design process for an inflatable parabolic torus reflector antenna is outlined. The development of suitable distortion models is presented and representative RF characteristics are given. These RF characteristics include farfield patterns, beam contour pattern, beam efficiency and other key performance parameters, The development of an advanced analytical modeling/numerical tool in support of the design effort is also detailed