IEM kvarz and quartzlocks's GPS-disciplined rubidium frequency and time standard

摘要

IEM Kvarz and Quartzlock have devised a GPS-disciplined rubidium frequency and time standard to 10~(-14) level accuracy. As a result of employing unique carrier phase tracking techniques with algorithmic weighting of "all-in-view" software clock techniques with an excellent OCXO or rubidium oscillator built in, both short-term stability (STS) at 10~(-13) level and long-term stability (LTS) to 10~(-14) is realized. Now IEM Kvarz and Quartzlock have reduced the overall size and most importantly introduced temperature control for both the antenna and the downconverter, receiver, and processor. The original quad helix antenna eliminates multipath errors and the need for a choke plate, while the downconverter at the antenna means that the coax carries only 90 MHz, so it can be very long and thin (not short and fat for 1.5 GHz). Time output accuracy meets GPS time transfer atomic clock comparisons at < 5 ns, while LTS can be little improved, and STS has wander, noise floor, and holdover built to the 10~(-14) level. IEM Kvarz and Quartzlock have now exceeded even high performance commercial cesium stability at only 20percent of its cost and the need to employ a hydrogen maser test to maintain 10:1 integrity margin above GPS (and cesium) performance.