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Time and Frequency Measurements

Characterization of Oscillators and Amplifiers

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Technical Contacts:
David Howe
Tel: 303-497-3277
E-mail: dhowe@boulder.nist.gov

Stefania Romisch
Tel: 303-497-3446
E-mail: stefania.romisch@nist.gov

Trudi Peppler
Administration and Logistics
Tel: 303-497-3338
Fax: 303-497-6461
E-mail: tpeppler@boulder.nist.gov

Please contact the technical staff before shipping instruments or standards to the address listed below.

Mailing Address:
National Institute of Standards and Technology
M.C. 847
325 Broadway
Boulder, CO 80305-3328

Service ID
Number
Description of Services Fee($)
77100C Oscillator Frequency Calibration At Cost
77110C Characterization of Atomic Frequency Standards At Cost
77120C Characterization of Oscillators:Time Domain At Cost
77130C Characterization of Oscillators and Amplifiers: Phase Noise in the Frequency Domain At Cost
77131C Characterization of Oscillators and Amplifiers: Amplitude Noise in the Frequency Domain At Cost
Fees are subject to change without notice.

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Oscillator Frequency Calibration (77100C)

NIST provides calibration services for oscillators with an output frequency of 1 Hz to 50 GHz. The relative standard uncertainty is nominally that of the NIST frequency standard, which is 5 x 10-15, but is limited by noise in the oscillator under test. The frequency stability of the oscillator can also limit the calibration, because oscillators often change frequency during shipment. Higher frequencies (50 Hz to 110 GHz) are covered under Service ID Number 77140S.

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Characterization of Atomic Frequency Standards (77110C)

An atomic standard NIST characterizes by introducing it as a member of the NIST time scale system. The output of the standard is sampled every 2 h in sequence with the other clocks in the time scale, and the performance of the standard under test is readily determined. The standard test involves 30 d of measurements. The square root of the Allan variance σ y (τ) is measured to 3 x 10-15, for averaging times of 7200 s to 106 s. The relative standard uncertainty of the time scale is 5 x 10-15 and the fractional frequency drift is less than 2 x 10-16 per day. The actual values transferable to the standard are often limited by the oscillator's stability and noise properties.

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Characterization of Oscillators: Time Domain (77120C)

NIST provides services to calibrate oscillator frequencies of 5 MHz, 10 MHz, and 100 MHz. The stability in terms of the square root of the Allan deviation σ y (τ) is determined by repeated measurements at 0.5 s intervals σ y (τ) is determined to 4 x 10-13/t-1/2 for averaging times of 0.5 s to 10 000  s and frequency offset is measured with a relative standard uncertainty of 5 x 10-15, limited by the noise level and type in the oscillator under test. The frequency measurement transferable to the oscillator is often limited by the oscillator's stability due to transport between laboratories and on-off cycling. Measurements of Allan deviation from approximately 1 µs to 0.5 s can be determined by integration of the oscillator phase noise. This inversion of the data is performed by NIST. Thus, measurements in this range should be done under Service ID Numbers 77130C or 77140S. Characterization of time domain stability at other frequencies is covered under Service ID Number 77140S.

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Characterization of Oscillators and Amplifiers: Phase Noise in the Frequency Domain (77130C)

NIST provides calibration services of the phase noise of single oscillators and amplifiers. For frequencies of 5 MHz to 26 GHz, phase modulation (PM) noise Sφ(ƒ) of single oscillators and amplifiers can be determined for Fourier frequency offsets from the carrier of 0.1 Hz to 10 MHz. The PM noise is measured for only a few user-specified frequency offsets (typically 3 points per decade). All measurements of phase noise are made relative to 1 rad 2 /Hz. At a carrier frequency of 5 MHz, Sφ(ƒ) can be measured to -145 dB for a frequency offset of 1 Hz and -190 dB for an offset of 10 kHz. At a carrier frequency of 100 MHz, Sφ(ƒ)can be measured to -50 dB for a frequency offset of 1 Hz and -190 dB for an offset of 50 kHz. A typical value of standard uncertainty is 1 dB, but specific values depend on the carrier frequency and the offset frequency. Specific measurement requirements should be discussed prior to placing an order. PM noise for frequencies above this range (but less than 110 GHz) are covered under Service ID Number 77140S.

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Characterization of Oscillators and Amplifiers: Amplitude Noise in the Frequency Domain (77131C)

NIST provides calibration services of amplitude noise of single oscillators and amplifiers. For frequencies from 1 MHz to 26 GHz, amplitude modulation (AM) noise Sα(ƒ)of single oscillators and amplifiers can be determined for Fourier frequency offsets from the carrier of 0.1 Hz to 10 MHz. The AM noise is measured for only a few user specified frequency offsets (typically 3 points per decade). All measurements of amplitude noise are made relative to 1 Hz. At a carrier frequency of 5 MHz, Sα(ƒ) can be measured to -140 dB for a frequency offset of 1 Hz, and -180 dB for an offset of 10 kHz. At a carrier frequency of 100 MHz, Sα(ƒ) can be measured to -30 dB for a frequency offset of 1 Hz and -180 dB for an offset of 50 kHz. A typical value of standard uncertainty is 1 dB, but specific values depend on the carrier frequency and the offset frequency. Specific measurement requirements should be discussed prior to placing an order. AM noise for frequencies above this range (but less than 110 GHz) are covered under Service ID Number 77140S.

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References—Calibration and Characterization of Oscillators and Amplifiers

Introduction to the Time Domain Characterization of Frequency Standards, J. Jesperson, Proc. 25th Annu. Precise Time and Time Interval (PTTI) Meeting, Pasadena, CA, 83-102 (Dec. 1991).

An Introduction to Frequency Standards, L. Lewis, Proc. IEEE 79 (7), 927-935 (July 1991).

Properties of Signal Sources and Measurement Methods, D. A. Howe, D. W. Allan, and J. A. Barnes, in Characterization of Clocks and Oscillators, edited by D. B. Sullivan, D. W. Allan, D. A. Howe, and F. L. Walls, Natl. Inst. Stand. Technol. Tech. Note 1337, 14-16 (1990).

Characterization of Clocks and Oscillators, D. B. Sullivan, D. W. Allan, D. A. Howe, and F. L. Walls, eds., NIST Tech. Note 1337 (Mar. 1990).

Frequency and Time-Their Measurement and Characterization, S. R. Stein, Precision Frequency Control, Vol. 2, edited by E. A. Gerber and A. Ballato (Academic Press, NY), 191–232 (1985).

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Program questions: Calibrations
Phone: 301-975-5454, Fax: 301-975-2950
NIST, 100 Bureau Drive, Stop 8363, Gaithersburg, MD 20899-8363