Triple redundant precision frequency reference for commercial space applications

This paper describes a redundant quartz crystal based frequency reference developed for commercial space applications. This product is an outgrowth of many years of experience providing similar functionality for military space applications, but is optimized for low cost, short cycle time commercial space applications. This device provides 3 for 1 redundancy, 8 to 24 outputs for distribution to satellite subsystems, and low power dissipation (<5 W) in a radiation hardened package designed to provide a 20 year operational life. The frequency can be remotely set from the ground with a resolution of 1E-11. Performance data for this device, both from terrestrial and space measurements, are presented, demonstrating frequency aging of <3E-11/day, and very low phase noise (floor <-165 dBC).