Design of Low Additional Stability Multi-channel Digital Phase Comparator

In this paper, the multi-channel low additional stability phase comparator is designed and fabricated based on the technique of digital double mixing cascaded analog double mixing while noise suppression is used in the frequency doubling link. Compared to the single analog double mixing technique, the method presented in this paper is more advanced in the low additional stability. When the input frequency is 10 MHz, the additional stability reaches 1.7E−14@1s 2.7E−15@10s, 4.6E−16@100s, 1.37E−16@1000s, 4.4E−17@10000s. The multi-channel comparator designed in this paper will satisfy the requirement of high performance atomic clocks in the time keeping lab and novel frequency clocks and microwave sources.