Title :
A low-frequency high resolution digital synthesizer
Author :
Giffard, Robin P. ; Cutler, Leonard S.
Author_Institution :
Hewlett-Packard Labs., Palo Alto, CA, USA
Abstract :
A high-resolution digital frequency synthesizer was designed to provide modulation and fine frequency interpolation in a new cesium frequency standard. Requirements include resolution, spectral purity, phase-continuous frequency modulation, simplicity, and low power. The authors describe how these requirements were satisfied with a direct digital frequency synthesizer (DDFS). The DDFS consists of a 34-b phase accumulator feeding a 14-b wide address map and a 12-b digital-to-analog converter (DAC). For output frequencies in the range 131.0 to 132.5 kHz, the level of spurious sidebands, is less than -85 dBc. This is compatible with the expected performance of the DAC
Keywords :
atomic beams; atomic clocks; caesium; digital circuits; frequency measurement; frequency modulation; frequency synthesizers; measurement standards; 131 to 132.5 kHz; Cs frequency standard; atomic beam standards; clock frequency; digital-to-analog converter; direct digital frequency synthesizer; fine frequency interpolation; high resolution digital synthesizer; low power; low-frequency; phase accumulator; phase-continuous frequency modulation; spectral purity; spurious sidebands; Adders; Clocks; Digital modulation; Equations; Frequency modulation; Frequency synthesizers; Hydrogen; Laboratories; Masers; Probes;
Conference_Titel :
Frequency Control Symposium, 1992. 46th., Proceedings of the 1992 IEEE
Conference_Location :
Hershey, PA
Print_ISBN :
0-7803-0476-4
DOI :
10.1109/FREQ.1992.270015
