DocumentCode :
1125212
Title :
Frequency-Stability Measurement System Using High-Speed ADCs and Digital Signal Processing
Author :
Mochizuki, Ken ; Uchino, Masaharu ; Morikawa, Takao
Author_Institution :
Anritsu Corp., Kanagawa
Volume :
56
Issue :
5
fYear :
2007
Firstpage :
1887
Lastpage :
1893
Abstract :
We propose a novel measurement system that evaluates the frequency stability of high-precision oscillators such as atomic oscillators. This measurement system consists of a pair of high-speed analog-to-digital converters (ADCs) and digital-signal-processing (DSP) circuits on a field programmable gate array. The pair of high-speed ADCs simultaneously digitizes the two sinusoidal-voltage outputs from the oscillator under test and a reference oscillator. The DSP circuits calculate the phase difference between the two sinusoidal voltages. The frequency stability evaluated as the Allan deviation sigmay(tau) is calculated from the phase difference. The main advantage of this system is that the hardware configuration is much more compact than the conventional systems using a dual mixer and a local oscillator. Nonetheless, the system noise floor of the prototype at the nominal frequency of 5 MHz is sigmay(1000 s) = 6.8 times 10-17, which is sufficient to evaluate a commercial hydrogen maser oscillator and is better by a factor of 5 than our previously reported system. We have verified that the measurement accuracy of the prototype depends on the nominal frequency and the level of the sinusoidal voltages, but it does not depend on the initial phase difference and offset frequency.
Keywords :
analogue-digital conversion; circuit stability; digital signal processing chips; field programmable gate arrays; frequency stability; measurement systems; oscillators; Allan deviation; DSP circuits; aperture jitter; atomic oscillators; digital signal processing; digital-signal-processing circuits; dual mixer; field programmable gate array; frequency 5 MHz; frequency-stability measurement system; hardware configuration; high-precision oscillators; high-speed ADC; high-speed analog-to-digital converters; hydrogen maser oscillator; measurement accuracy; offset frequency; sinusoidal voltage phase difference; system noise floor; Analog-digital conversion; Atomic measurements; Circuit stability; Digital signal processing; Field programmable analog arrays; Field programmable gate arrays; Frequency measurement; Oscillators; Prototypes; Voltage; Allan deviation; analog-to-digital converter (ADC); aperture jitter; digital signal processing (DSP); frequency stability;
fLanguage :
English
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9456
Type :
jour
DOI :
10.1109/TIM.2007.895588
Filename :
4303427
Link To Document :
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