A Study of Phased Array Antennas for NASA’s Deep Space Network

Abstract: Recently, the Jet Propulsion Laboratory (JPL) has begun an assessment of the long-term capability of the antennas of the Deep Space Network (DSN). Various alternative plans for upgrading or replacing the present 70-meter antennas have been considered. Several options have been studied which include modifying the present antennas for extended life and reliability, new 70-meter single aperture antennas with offset or symmetric feeds, 100-meter spherical antennas, an array of a few smaller 34-meter antennas, a much larger array (hundreds) of much smaller (5-10 meter) reflector antennas, and finally active planar phased arrays with millions of elements. In this paper we briefly discuss various options but focus on the feasibility of the phased arrays as a viable option for this application. Of particular concern and consideration will be the cost, reliability, and performance compared to the present 70-meter antenna system, particularly the gaidnoise temperature levels in the receive mode. Many alternative phased arrays including planar horizontal arrays, hybrid mechanically/electronically steered arrays, phased array of mechanically steered reflectors, multi-faceted planar arrays, phased array-fed lens antennas, and planar reflect-arrays are compared and their viability is assessed. Although they have many advantages including higher reliability, near-instantaneous beam switching or steering capability, the cost of such arrays is presently prohibitive and it is concluded that the only viable array options at the present are the arrays of a few or many small reflectors. The active planar phased arrays, however, may become feasible options in the next decade and can be considered for deployment in smaller configurations as supplementary options. 1