Expanding CubeSat Capabilities with a Low Cost Transceiver

CubeSats have developed rapidly over the past decade with the advent of a containerized deployer system and ever increasing launch opportunities. These satellites have moved from an educational tool to teach students about engineering challenges associated with satellite design, to systems that are conducting cutting edge earth, space and solar science. Early variants of the CubeSat had limited functionality and lacked sophisticated attitude control, deployable solar arrays and propulsion. This is no longer the case and as CubeSats mature, such systems are becoming commercially available. The result is a small satellite with sufficient power and pointing capabilities to support a high rate communication system. Communications systems have matured along with other CubeSat subsystems. Originally developed from amateur radio systems, CubeSats have generally operated in the VHF and UHF bands at data rates below 10kbps. More recently higher rate UHF systems have been developed, however these systems require a large collecting area on the ground to close the communications link at 3Mbps. Efforts to develop systems that operate with similar throughput at S-Band (2-4 GHz) and C-Band (4-8 GHz) have also recently evolved. In this paper we outline an effort to develop a high rate CubeSat communication system that is compatible with the NASA Near Earth Network and can be accommodated by a CubeSat. The system will include a 200kbps S-Band receiver and a 12.5Mbps X-Band transmitter. This paper will focus on our design approach and initial results associated with the 12.5Mbps X-Band transmitter.