Distribution, remote control and measurement of frequency stable, low phase noise standard signals

Research, development and application of two unique instruments providing improved solutions to the problems encountered in the distribution, remote control and measurement of frequency stable, low phase noise standard signals are described. One of these is an Auxiliary Output Generator (AOG) providing remotely and locally controllable variation of frequency and phase with unprecedented resolution and low noise using a 5 MHz reference standard. The AOG provides the function of a continuously variable phase or frequency shifter as well as a synchronizable one pulse per second output. The second instrument is a Time Domain Measurement System (TDMS) including an internal offset generator so that stability, frequency and phase measurements can be made with exceptional precision without changing the frequency or phase of the source. Design concepts and applications of these instruments are described and measurement sensitivities are presented in conjunction with stability curves illustrating the performance of Sigma Tau Standards Corporation atomic hydrogen masers.