Design and Implementation of a Deep Space Communications Complex Downlink Array

Abstract

This paper describes the design and implementation of a frequency domain beamformer that will downlink array the signals of up to eight 34-m or 70-m antennas at each of NASA’s three Deep Space Communications Complexes (DSCC). The array digitizes inputs with an Intermediate Frequency (IF) of 100 to 600 MHz, coherently combines the inputs digitally, and transforms the combined waveform back to analog. Real-time correlation measurements are used for delay and phase calibration, allowing the system to adjust for atmospheric variations. A DSCC Downlink Array system is operational at each DSCC. Initial results from passes with the New Horizons spacecraft are presented and system performance is analyzed.