Low-Noise and Stable LO’s for Deep Space Applications

Abstract

The traditional role of local oscillators in communications systems is much expanded in the NASA’s Deep Space Network (DSN) which supports communications, tracking, and radio science experiments associated with interplanetary missions such as Voyager, Ulysses and Galileo. In this world-wide network of three complexes, local oscillators provide spectrally pure signals in receivers which track spacecrafts as far away as the edge of the solar system. Spectrally pure signals are also crucial to the success of a variety of radio science investigations studying interplanetary particles, and planetary rings and atmospheres. Finally, local oscillators function as flywheels in advanced frequency standards currently under development for the DSN, and influence the ultimate stabilities obtainable with such devices.