  The next-generation Very Large Array (ngVLA) is an astronomical observatory
planned to operate at centimeter wavelengths (25 to 0.26 centimeters,
corresponding to a frequency range extending from 1.2 to 116 GHz). The
observatory will be a synthesis radio telescope constituted of approximately
244 reflector antennas each of 18 meters diameter, and 19 reflector antennas
each of 6 meters diameter, operating in a phased or interferometric mode. We
provide a technical overview of the Reference Design of the ngVLA. This
Reference Design forms a baseline for a technical readiness assessment and the
construction and operations cost estimate of the ngVLA. The concepts for major
system elements such as the antenna, receiving electronics, and central signal
processing are presented.
