Digital frequency generation in atomic frequency standards using digital phase shifting
US5721514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1996 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Jul 11, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/26
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In the generation of frequency-modulated interrogation frequencies for atomic frequency standards, the modulation characteristics can be tailored to the frequency discrimination characteristics of a physics package. The rate of phase change of a digital pulse train providing a frequency-modulated component of interrogation frequency for an atomic frequency standard can be varied, for example, by multiplexing a plurality of differently phased (delayed) pulse trains to vary the rate of phase change in a digital interrogation frequency component, or by effecting phase delays and phase advances through the addition and subtraction of pulses of a digital interrogation frequency component. In addition, fine frequency and/or modulation depth control, which can overcome physics package frequency offsets, can be effected through the addition and/or subtraction of increments of phase to and/or from a digital frequency component of the interrogation frequency at a variable phase change frequency (or drop rate count) to provide variable rates of phase change in alternate half-cycles of the modulation frequency in the synthesis of a frequency-modulated interrogation signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.