X-band digital receiver for the New Horizons spacecraft

A low-power X-band digital uplink receiver has been developed by the APL for NASA's planned New Horizons mission to Pluto and the Kuiper Belt, which is scheduled to launch in January 2006 with a Pluto encounter as early as 2015. The uplink receiver provides X-band carrier tracking, command detection/demodulation, critical command decoding, ranging tone demodulation, and built-in radiometrics modes. The primary RF carrier tracking, command detection, and ranging requirements are similar to those of predecessor deep space RF systems, including both the small deep space transponder (SDST) and CONTOUR RF transceiver systems. Additional design requirements for radioscience compatibility and reduced power consumption led to a new design approach. The new receiver design makes use of digital processing techniques and revised system architecture to meet these new requirements, while at the same time enhancing performance and flexibility over predecessor systems. A 53% to 68% reduction in secondary power consumption over comparable predecessor systems has been achieved. This paper provides a detailed description of the new low-power digital receiver design.