| Time signal generator is a device that can provide users with the required time signal and time-code signal.The main way of approaching this is to receive signals from units which are standard sources of atomic clocks.The frequency integrated processing is used to produce various frequency pulse signals,IRIG-B signals and other time-signals for use of other systems or devices.This thesis is meant to meet the requirements and performance requirements of a space engineering project.In the project DDS based on the AD9854、CPLD based on the XC95216 and the signal into unit、the code generater unit、MPU unit、the signal output has been designed.A set of test system is designed to verify whether the technical index meets engineering application requirements.The main technical innovation and technical difficulties include,The low noise frequency-pulse conversion technique is adopted,the low insertion loss is introduced in the transition process of frequency to pulse.And the method of applying dephasing can achieve the precision phase shift,and the phase shift resolution can reach 10 ps.In performance,the device can produce high-precision pulses and time signals,maintain synchronized with local time;The nondestructive switching of input frequency signal can be realized,so that the output pulse signal does not occur or increase or decrease pulse when switching.The output pulse signal does not occur when the pulse output signal is selected.The output signal front width is small,the signal jitter is small,can carry on the large-scale precision shift phase.The device has been completed,It can produce all commonly used time signals at the same times,various technical indicators meet the requirements,the pulse phase jitter less than or equal to 30 ps,the pulse phase consistency less than or equal to 2ns.At present,the equipment has been delivered to the whole and applied in a space engineering project.The performance is stable,and the system indicators are at the leading level of similar products in China. |
