Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 06, 2024 - December 07, 2024
This paper describes a feasibility study conducted on applying a reflector-based digital beam forming (DBF) synthetic aperture radar (SAR) to small X-band SAR satellites. The study assumes to use 3.6 m diameter deployable reflectors and DBF units (DBFU). Fan-fold deployable reflectors, which are researched and developed to apply for Ka-band geostationary communications satellites, are employed for this study. The DBFU is designed with a central frequency of 9.8 GHz and a band width of 1,200 MHz. With a reflector diameter of 3.6 m, an antenna tower capable of accommodating a 2 m-long stowed reflector was necessary. Based on this configuration, a structural mass of under 50 kg and the first natural frequency at 20.5 Hz were accomplished. An 8-channel DBF unit (DBFU) with a 1,200 MHz bandwidth was designed using FPGA technology, and it was confirmed that the required processing speed for DBF operations could be achieved. For the reflector, by setting facet sizes for 9.6 GHz, 1.6 mmRMS surface accuracy was achieved. Based on these results, the feasibility of a reflector-based DBF SAR system for a small X-band SAR satellite was confirmed.
