--V.F. Kroupa, Institute of Radio Engineering and Electronics, Academy of Sciences of the Czech Republic

In the tutorial we will discuss basic equations of PLL, investigate 1^st, 2^nd, 3^rd, and higher order loops with computer solution of the transfer functions and phase margin characteristics.  Furthermore we will proceed with transient responses to the step and periodic phase and frequency disturbances. We shall investigate sampling processes and discuss principles of loop stability from the point of modern computer applications together with Pull-in and Lock-in times. Special attention will be given to the noise properties and finally, we will pay attention to the problems of z transform approaches. 

Vênceslav F. Kroupa, PhD. received the Ing. degree (M.Sc. diploma) in Electrical Engineering from Prague Technical University, Ph.D., and DrSc. degree from the Czechoslovak Academy of Sciences, Prague.  In 1955 he joined the Institute of Radio Engineering and Electronics of the Czechoslovak Academy of Sciences, now Academy of Sciences of the Czech Republic with affiliation as a consultant.

For the past 50 years his major scientific and research interests have been standard time and frequency, frequency stability and noise, frequency synthesis, precise frequency measurements, and phase locked loops.  On these subjects he has written 5 books and published over 100 technical papers and reports. He holds 15 patents.  Dr. Kroupa is senior member of IEEE, associated with the Ultrasonics, Ferroelectronics, and Frequency Control Society.

Advanced Atomic Clocks

--L. Maleki, Jet Propulsion Laboratory

Recent advances in atomic physics and particle trapping technologies have led to important developments in the science and technology of atomic clocks.  New standards based on ion traps, and on laser cooled neutral atoms have already produced the highest stability, and the best accuracy reported to date.  These techniques also hold the promise for increased performance for future atomic clocks, in support of ground and space based applications.  In this tutorial the physics of atomic clocks will be reviewed, and the role of the new technology in advancing the performance of atomic time and frequency standards will be described.  The physics of ion traps, and light traps for neutral atoms will be reviewed, and details of clocks based on these advances will be described.  Some applications of advanced atomic standards will also be reviewed.

Lute Maleki is a principle member of the technical staff and the Technical Group Supervisor of the Time and Frequency Science and Technology Group at JPL.  His current research interest include ion confinement and trapped ion frequency standards, development of laser-cooled atom traps, study of various aspects of the physics of frequency standards, photonics reference frequency generation and distribution, investigations of the noise and stability properties of rf and optical frequency sources, and test of fundamental laws of physics using atomic clocks.  He received his B.S. In Physics from the University of Alabama in 1969 and his Ph.D. in Experimental Atomic Physics in 1975 from the University of New Orleans (Louisiana State Universities).  Dr. Maleki is a member of the American Physical Society, and the Optical Society of America and a Fellow of the IEEE.

An Introduction to the Wavelet Analysis of Time Series

--D.B. Percival, University of Washington, Seattle

In recent years the discrete wavelet transform (DWT) has become a popular tool for analyzing time series. The DWT decomposes a time series with respect to both time and scale and hence is particularly useful for analyzing time series that exhibit variations with respect to both these independent variables. The DWT of a time series leads to an additive decomposition (known as multiresolution analysis) and to an analysis of variance (known as the wavelet variance), both of which can be useful tools for time series analysts.  This tutorial is intended to be a basic introduction to wavelet analysis, with emphasis on wavelet-based techniques of most interest to the frequency control community.  After a discussion of the basic form of the DWT and how it compares to the discrete Fourier transform, we will describe the maximal overlap DWT (MODWT), which is a `shift-invariant' version of the DWT.  We will then discuss how the DWT and MODWT can be used to estimate the parameters for power law processes (often assumed as models for phase and fractional frequency fluctuations).  We will note connections between the wavelet variance and the well-known Allan variance and discuss methods for determining confidence intervals for the wavelet variance. Finally we will briefly comment on other ways in which wavelets might be useful in frequency and timing applications and briefly review popular software for wavelet analysis.

Donald B. Percival is a Senior Mathematician at the Applied Physics Laboratory, University of Washington; a Senior Research Scientist at MathSoft, Inc., Seattle; and an Affiliate Associate Professor, Department of Statistics, University of Washington. He received a B.A. from the University of Pennsylvania (1968; astronomy); an M.A. from George Washington University (1975, mathematical statistics); and a doctorate from the University of Washington (1982, statistics).  From 1968 to 1978 he was an Astronomer with the Time Service Division of the US Naval Observatory in Washington, DC, where he worked on the generation of atomic clock time scales and on the analysis of the frequency stability of high-performance oscillators.  He is the co-author (with Andrew Walden) of the Cambridge University Press books "Spectral Analysis for Physical Applications" (1993) and "Wavelet Methods for Time Series Analysis" (to appear in July 2000).

Fundamental of X-Ray Orientation of Quartz Crystals

--J. Kusters, Agilent Technologies Inc.

This short tutorial will address the basic technologies used in determining the orientation of a quartz crystal.  Included will be discussions of the basic principles of various X-ray systems, a discussion of the Miller Bravais Coordinate system, a derivation of the Bragg relationship, calculation of basic crystal lattice spacing, Laue diffraction systems, and determination of practical X-ray angles.  The talk concludes with a discussion of a quality control technique developed at Agilent in the determination of effective lattice constants as part of an incoming qualification program for quartz crystal blanks.

Mr. Kusters is currently the Manager of the Precise Time and Frequency operation at Agilent Technologies’ Santa Clara site.  His technical specialties are time and frequency devices, equipment, and measurement techniques.  He was the program manager for the Agilent 5071A Primary Frequency Standard, and is the recipient of the IEEE Cady and Sawyer Awards, and the EIA Larsen and Staudte awards for his work in quartz technology and the development of the SC-cut.

Clock Jitter

--R. Temple, Agilent Technologies Inc.

The term jitter refers to the fluctuations in many physical quantities.  In the frequency control field, jitter may refer to fluctuations in phase, frequency, time, or amplitude and these fluctuations may be characterized in the time domain or the frequency domain. In addition jitter may refer to the total fluctuations of a quantity under the specified conditions or it may refer to the variation in a quantity after a particular time interval without regard for any variations at intermediate times.

This tutorial will describe several of these jitter types and the parameters that must be specified to completely characterize them.  Measurements of the spectral density of phase fluctuations as a function of modulation rate or offset frequency, f, i.e. phase noise measurements, will then be used to calculate example numerical values for some of these jitter types. These calculations will proceed from straightforward cases using sine wave modulation to more complicated examples using typical device phase noise plots. A simple graphical rule of thumb for estimating jitter will be shown. Modest sources will be shown to be capable of sub-picosecond jitter. Time domain methods of jitter measurement will not be discussed in this tutorial.

Dr. Temple received a BA in physics from Harvard University in 1961 and an MS and Ph.D. in Electrical Engineering in 1965 and 1971 respectively from the University of Colorado. His thesis title was "The Operation and Frequency Stability Measurement of a Hydrogen Cyanide Beam Type Maser".  He joined Hewlett-Packard in 1969 and contributed to the development of frequency synthesizers and a spectrum analyzer. He has since participated in the development and application of three generations of phase noise measurement systems.

Photonic Techniques in Frequency and Timing

--X.S. Yao, Jet Propulsion Laboratory

Because of its advantages of low loss, low dispersion, high speed, wide bandwidth, light-weight, and immunity to electromagnetic interference, fiber optics gradually finds its way into traditionally RF-technology dominated field of frequency and timing.  On the other hand, due to their electro-optic hybrid nature, fiber optic systems require special hybrid signal sources that cannot be fulfilled with traditional RF technologies.  In this tutorial, we discuss how photonic techniques can be used for frequency and timing, especially for generating hybrid signals for fiber optic systems.  In particular, we will cover the following topics: the basics of fiber optics and characteristics of fiber optic components, noise sources in photonic systems, photonic technology for frequency standard transmission & distribution, photonic technology for frequency multiplication, up-conversion and down conversion, photonic techniques for signal generation, including optical heterodyne method, lasers mode-locking method (active & passive), laser self-pulsation, opto-electronic oscillator, and coupled opto-electronic oscillator.

X. Steve Yao is a senior member of the technical staff at the Jet Propulsion Laboratory, California Institute of Technology, engaging in the research and development of advanced ultrastable microwave fiber optic devices and systems.  He has broad interests in microwave photonics and nonlinear optics and has authored numerous papers in the areas of photonic and down-conversion, Brillouin selective sideband amplification of microwave signals, photonic frequency multiplication, nonlinear optical effects on fiber communication systems, optically controlled phased array antennas, and optical pulse coupling in photorefractive crystals.  He is also the holder of several patents, including the optoelectronics oscillators.  Dr. Yao received the M.S. and Ph.D. degrees in electrical engineering/electrophysics, in 1989 and 1992 respectively, from the University of Southern California.

The Fundamental Theory of Low Noise Oscillators with Special Reference to Some Detailed Designs

--J. Everard, University of York, UK

This tutorial will describe the theories (based on simple models) required to design low noise oscillators.  These theories will be used to predict the optimum conditions for minimum phase noise.  These include: the optimum coupling coefficient of the resonator to the amplifier expressed in terms of Q_L/Q₀ and hence closed loop amplifier gain; the open and closed loop phase error; the coupling of the varactor into the oscillator either within the resonator or as a phase/frequency shifter within the loop; the effect of bias line noise; large signal modeling to obtain O/P power and harmonic content.

These theories will then be used in detailed examples to design an inductor capacitor based RF oscillator and a transmission line microwave oscillator.  Simulation tools will be used to confirm operation of the resonators and illustrate the effect of parasitics.  Phase noise results are usually within a 1-3dB of the theoretical minimum.

Jeremy Everard graduated from King's College London in 1976 and obtained his PhD from the University of Cambridge in 1983.  He worked for six years at Marconi Research Laboratories, M/A-Com and Philips Research Laboratories on Radio and Microwave circuit design.  At Philips he ran the Radio Transmitter Project Group.  He then taught RF and Microwave Circuit design, Opto-electronics and Electro-magnetism at King's College London for nine years.  He became University of London Reader in 1990 and Professor of Electronics at the University of York in 1993. 

His current research interests in Opto-electronics include: All optical self-routing switches which redirect laser beams according to the destination address encoded within the data signal, ultra-fast 3-wave opto-electronic detectors, mixers and phase locked loops and distributed fiber optic sensors using Raman and Brillouin scattering. In the RF/Microwave area his interests include: The theory and design of low noise oscillators using inductor capacitor, SAW, crystal, dielectric, transmission line, helical and superconducting resonators; flicker noise measurement and reduction in amplifiers and oscillators; high efficiency broadband amplifiers; high Q printed filters with low radiation loss and MMIC implementations. He has published 55 papers and co-authored a book on Gallium Arsenide applied to Circuits and Systems. He has filed 16 patent applications.  He is a member of the IEE, London, UK and the IEEE.