Reconfigurable, Radiation Tolerant S-Band Transponder for Small Satellite Applications

Reconfigurable, Radiation Tolerant S-Band Transponder for Small Satellite Applications

Southwest Research Institute (SwRI) has developed a reconfigurable, radiation tolerant, communication system that addresses the needs for low-cost, quick turn spacecraft, as well as the reliability and connectivity required in harsh radiation environments of higher orbit systems. The core of such a Flexible Communication Platform (FCP) is a Software Defined Radio (SDR) architecture, currently providing S-Band (2 GHz) communications but expandable to other frequencies. The Digital Processing Unit (DPU) is a PC/104 slice that can be used as a standalone radio with an onboard RF chip for LEO environments or can be augmented with an RF front-end on a separate slice. The architecture of the DPU is based around an SRAM-based FPGA. SRAM-based FPGAs, however, have significant limitations in spacecraft systems due to radiation susceptibility of the FPGA programming cells. SwRI chose to implement a combination of triplicated logic (TMR) and Configuration Memory Scrubbing, specifically in an external RAD-Hard device, to mitigate radiation effects on the system. The flexible design of the DPU all ows rapid integration into multiple target mission architectures. When coupled with the RF front-end, the FCP is capable of communicating from LEO and MEO orbits using a variety of wideband signals and protocols.