The Design and Realization of a High Precision DPLL Based on Frequency Aided
Yanlong Zhang, Shilian Wang, Zhang Er-yang · Electronic Engineer · 2008
For the need of high-precision pure tone ranging in a deep-space USB (Unified S Band) meas- urement and control system,a new high-precision DPLL based on the frequency of measurement and second mixer is presented.It consists of high precision frequency measurement module,digital mixing module,deci- mation filter module,second-order digital phase-locked loop module etc.The concept is realized through pro- grammable language VHDL and is based on programmable logic devices XC4VLX100 platforms.The operation is stable when CNR of input is 25 dB.Hz and loop noise bandwidth is 30 Hz.The test results show that the DPLL meets the requirements of the system design and meets the relevant parameters are achieved.