Research on measurement technology of dual-mixer time difference

To measure the frequency deviations of two frequency sources, we can examine the time difference. Cause the low precision of direct measurement can´t meet the high accuracy requirement. Dual-mixer time difference measurement can improve the measurement accuracy. This paper introduced the principle of dual-mixer time difference measuring and contribution to frequency measurement of high accuracy and high frequency resolution; raised a new concept of triple samples variance used in measurement of dual-mixer time difference; and gave suggestions in improving DMTD measuring capabilities.