Abstract：To reduce the microwave leakage-induced uncertainty, a Mach-Zehnder interferometric switch was applied in the interrogation microwave synthesizer of NIM5 Cesium fountain clock. The interferometric switch may introduce the phase transient. Meanwhile, other microwave and electronic parts in fountain clock may also introduce phase transient. The phase transient induces frequency shift and uncertainty. To evaluate the frequency shift and uncertainty, the phase transient Realtime measurement was taken on interrogation microwave synthesizer by home made triggered phase transient analyzer. The seven days continuous measurement result shows that the frequency shift and uncertainty are in 10-16 level, and 100Hz periodic phase transient are found. The periodic phase transient may come from the interrogation microwave synthesizer, which need be researched and improved further.
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2015, Vol. 36 
