Resources for Precision Timing, Stability, and Noise Analysis

2010 Microwave Update conference slides

Frequency Stability Measurement - Technologies, Trends, and Tricks (2 MB .PDF)

General timing and noise metrology

W. J. Riley's IFCS 2003 tutorial slides Techniques for Frequency Stability Analysis -- one of the best technical overviews and bibliographies I've seen. Riley's own references page is also useful.

Good collection of tutorials from IEEE-UFFC on time, frequency, and jitter/noise measurement, ranging from introductory to advanced

An Introduction to Frequency Standards, Lindon L. Lewis

NIST's Time and Frequency Division offers a collection of metrology links with content ranging from basic tutorial guidance to leading-edge research. Also see their table of General Interest Time and Frequency Publications and Properties of Oscillator Signals and Measurement Methods.

Q&A examples from the annual NIST Time and Frequency Metrology Seminar

Wenzel's Time & Frequency Articles page is an excellent collection of practical insights and techniques.

HP's Q2 1994 Bench Briefs has a brief introductory article on time base oscillator and frequency standard calibration.

This copy of NIST Technical Note 1337, Characterization of Clocks and Oscillators, is very handy because it actually includes reprints of some key papers with errata and discussion transcripts. 23 MB, and worth it!

Rick Fisher at NRAO has posted a good explanation of various Astronomical and other standard time scales also includes handy FORTRAN code links.

Tom Van Baak's needs no introduction to those already steeped in the dark arts of amateur time metrology. Other personal sites worth checking out include John Ackermann, N8UR's page at and Brooke Clarke's Time & Frequency resources.

Didier Juges's Timing page contains several useful links including a very useful wiki. Some of the most valuable information on is hidden in Bruce Griffith's collection of notes on precision time and frequency systems, including low-noise design practices. An hour on Bruce's page can save you a day on the NIST site, or a week in the lab.

Examples of 1 PPS Clock Measuring Systems, W. J. Riley

Some papers and presentations by Sam Stein of Symmetricom (formerly Timing Solutions Corporation):

Manufacturer-specific app notes and resources

Application Notes: Agilent and HP Frequency Counter Products Selections from this page include:

FTP directory on containing various docs and support files for the 3048A, 70428A, E5500 series, and other PN instrumentation

Joe Geller's page on the HP 53310A modulation-domain analyzer

Agilent Radar Measurements isn't specifically about timing, noise, or stability analysis... but it's a very well-written app note nevertheless, covering the timing/noise aspects of radar metrology and many others as well.

Technology-specific app notes and resources



Software, statistical math, and instrumentation algorithms

Perhaps second only to NIST itself is the collection of links at Hamilton Technical Services, home of W. J. Riley's Stable32 program. Stable32 is a well-respected "gold standard" among time/frequency stability analysis software packages -- in fact, NIST's Handbook of Frequency Stability Analysis was written by Riley, and is similar in content to Stable32's user manual. Although not free, Stable32 is very popular among professionals in the field. Measurements made in TimeLab and other acquisition packages are often exported to Stable32 for in-depth manipulation, cleanup, and analysis.

Spur Detection, Analysis, and Removal Specific notes on spur processing in Stable32

Enrico Rubiola's The cross-spectrum experimental method details some of the key statistical concepts behind the cross-spectrum averaging technique as it applies to PN measurement. Steve Hageman offers an even simpler explanation here; his blog makes for some great reading in general.

Rubiola's presentation for IFCS 2012, High-resolution time and frequency counters, contains a survey of interpolation techniques and statistical algorithms associated with modern commercial counters.

Plotter by Ulrich Bangert, DF6JB, can be thought of as a freeware Stable32 competitor. Although Plotter doesn't handle data acquisition directly, it's a simple, lightweight program with a surprisingly deep array of features for plotting and analysis.

My own application for time/frequency measurement, TimeLab, is currently under active development. In addition to supporting the HP 5370A/B, Stanford Research Labs SR620, and other popular counters, TimeLab also allows you to acquire and analyze data from Symmetricom's TSC 5120A and other advanced instrumentation, including the TimePod timing/phase noise analyzer. New versions of TimeLab are posted regularly.

Some useful app notes on jitter and modulation analysis with VISI 7 and the Wavecrest SIA-3000 can be found on the Gigamax Technologies site.

Phase noise and jitter

Phase Noise and AM Noise Measurements in the Frequency Domain (NIST)

Wenzel Associates, purveyors of fine crystal oscillators and other precision frequency-control hardware, offers a collection of app notes and articles including hints and tips on low-noise design and a simple quadrature PLL for PN measurement. Some notes on a low noise amplifier for PN measurement are also available.

Martein Baaker, PA3AKE has a very nice H-mode mixer project page at that includes a discussion of LO noise and its effect on transceiver front-end performance. The emphasis is on DDS phase noise and coherent artifacts. Special attention is given to the underrated topic of power supply regulator noise. If you're working with newer DDS parts from Analog Devices you do not want to overlook Martein's work! He also includes a detailed page on his quadrature-PLL implementation for noise measurement.

Leif Åsbrink, SM5BSZ, author of Linrad, offers some worthwhile notes on low-noise crystal oscillator design and measurement.

Iulian Rosu, VA3IUL's site hosts a great collection of technical notes, among them Phase Noise in Oscillators.

The GPIB Toolkit's FAQ includes some links to classic HP seminar notes and other documentation on phase-noise measurement, reproduced here for ease of reference:

Analog Dialogue V42 #1 (2008) has a nice article on the causes and cures of ADC/DAC clock jitter, with charts and figures that didn't make it into any of their other books or app notes..

More from Analog Devices: AN-1067, The Power Spectral Density of Phase Noise and Jitter: Theory, Data Analysis, and Experimental Results

From Tektronix: Analyzing Clock Jitter using Excel

Guidelines for Designing BJT Amplifiers with Low 1/f AM and PM Noise A useful IEEE paper by Eva S. Ferre-Pikal, Fred Walls, and Craig Nelson that discusses residual noise in bipolar transistor amps for HF isolation and distribution.

Care and Feeding of High Speed Dividers Detailed app note from Zarlink discussing matching and layout issues associated with high-performance dividers such as the SP8400 series

AM noise

VHF Oscillator and Multiplier AM Noise (Wenzel)

More to come...

Back to John Miles, KE5FX home page