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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.43 [2005] >
IJPAP Vol.43(03) [March 2005] >
| Title: | Low-noise, high resolution microwave synthesis for atomic frequency standards |
| Authors: | Gupta, A Sen
Howe, D A |
| Keywords: | Atomic frequency standards
Microwave synthesis
Synthesizer
Cavity stabilized oscillator |
| Issue Date: | Mar-2005 |
| Publisher: | CSIR |
| IPC Code: | G 01 R 23/00, G 04 F 10/00 |
| Abstract: | The performance of newer generations of ultra high stability
atomic frequency standards based on laser cooled atoms and ions appears to be
limited by the local oscillator and the microwave synthesis chain. To improve
this performance, the design considerations of microwave synthesizers for Cs
hyperfine clock transition at 9.192 GHz that emphasize high resolution, low
phase modulation (PM) and amplitude modulation (AM) noise, low spurs near the
carrier, and very high phase stability with respect to environmental effects
have been studied. Typical performance achieved are: internal fractional
frequency stability of 1.5 × 10-15 at 10 s and
1 × 10-18 at 1 day;
fractional frequency step of 2 × 10-17 and
temperature coefficient less than 0.1-0.5 ps/K. Our design is quite general and
enables generation of microwave outputs corresponding to several different
atomic transitions. The phase locking of the synthesizer to a high stability
external frequency reference based on a cavity stabilized oscillator has been
studied. |
| Page(s): | 221-227 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.43(03) [March 2005]
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