Linear time-invariant (LTI) phase noise theories provide important qualitative design insights but are limited in their quantitative predictive power. Part of the difficulty is that device noise undergoes multiple frequency translations to become oscillator phase noise. A quantitative understanding of this process requires abandoning the principle of time invariance assumed in most older theories of phase noise. Fortunately, the noise-to-phase transfer function of oscillators is still linear, despite the existence of the nonlinearities necessary for amplitude stabilization. In addition to providing a quantitative reconciliation between theory and measurement, the time-varying phase noise model presented in this tutorial identifies the importance of symmetry in suppressing the upconversion of 1/f noise into close-in phase noise, and provides an explicit appreciation of cyclostationary effects and AM-PM conversion. These insights allow a reinterpretation of why the Colpitts oscillator exhibits good performance, and suggest new oscillator topologies. Tuned LC and ring oscillator circuit examples are presented to reinforce the theoretical considerations developed. Simulation issues and the accommodation of amplitude noise are considered in appendixes.

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Oscillator phase noise: a tutorial

A simple model describing the DC behavior of MOS transistors operating in weak inversion is derived on the basis of previous publications. This model includes only two parameters and is suitable for circuit design. It is verified experimentally for both p- and n-channel test transistors of a Si-gate low-voltage CMOS technology. Various circuit configurations taking advantage of weak inversion operation are described and analyzed: two different current references based on known bipolar circuits, an amplitude detector scheme which is then applied to a quartz oscillator with the result of a very low-power consumption (<0.1 /spl mu/W at 32 kHz), and a low-frequency bandpass amplifier. All these circuits are insensitive to threshold and mobility variations, and compatible with a CMOS technology dedicated to digital low-power circuits.

CMOS analog integrated circuits based on weak inversion operations

Vibration monitoring of rolling element bearings by the high-frequency resonance technique — a review

1 Introduction 2 Signals and Spectra 3 Signal Transmission and Filtering 4 Linear CW Modulation 5 Exponential CW Modulation 6 Sampling and Pulse Modulation 7 Analog Communication Systems 8 Probability and Random Variables 9 Random Signals and Noise 10 Noise in Analog Modulation Systems 11 Baseband Digital Transmission 12 Digitization Techniques for Analog Messages and Computer Networks 13 Channel Coding and Encryption 14 Bandpass Digital Transmission 15 Spread Spectrum Systems 16 Information and Detection Theory Appendix: Circuit and System Noise

Communication systems: an introduction to signals and noise in electrical communication

Algebraic manipulation covers branches of software, particularly list processing, mathematics, notably logic and number theory, and applications largely in physics. The lectures will deal with all of these to a varying extent. The mathematical content will be kept to a minimum.

Course notes

An unaltered reprint of the original Addison-Wesley edition of 1971. A textbook for a one-semester advanced undergraduate or graduate level course that deals with the understanding and use of devices and configurations of devices that bridge the gap between semiconductor or vacuum tube manufacture a

Communication Circuits: Analysis and Design

Presently available technology allows the construction of phase calibration equipment with phase resolutions of at least one part in 2/sup 18/, that is, a phase resolution of 0.00137 degrees . The users and the manufacturers of such equipment are faced with the practical problem of verifying their phase accuracy-both relative and absolute-and their traceability to some more accurate source. The authors present measurement methods that allow both relative and absolute high-resolution phase determinations in the vicinity of 0 degrees , 60 degrees , 90 degrees , and 180 degrees angles. They also present practical methods of implementing all of these methods together with comparative experimental data for all of them. >

Phase measurement, traceability, and verification theory and practice

A proven basic technique for the digital generation of two sine waves having a known and adjustable phase difference has been used to produce a commercial phase-angle standard. While the final performance for this instrument meets or exceeds those previously reported for a unit built by the National Bureau of Standards, a number of different circuit techniques have been used to achieve greater phase resolution, circuit simplifications, easier mechanisms for detecting possible circuit problems, and significant cost reductions.

Circuit techniques for use in a digital phase-angle generator

Described herein is a frequency modulation signal demodulation system which utilizes the amplitude modulation information inherent in a noise-corrupted frequency modulation carrier to control the parameters of a feedback loop, through which the demodulated FM information is passed, during the occurrence of large noise-induced, pulselike disturbances in the demodulated frequency modulation information. This function is performed by a circuit configuration which includes an amplitude modulation demodulator and a frequency modulation demodulator supplied in parallel from the input to the system for deriving information signals which are respective functions of the instantaneous envelope information and the instantaneous frequency modulation information. The control of the parameters of the feedback loop may be accomplished by the instantaneous envelope information directly or by the envelope information on which some process has been performed. The description also refers to the fact that the envelope detector may have linear or nonlinear characteristics. One way in which the envelope information may be processed is by a nonlinear quantizer followed by a time delay circuit which is interposed between the envelope demodulator and the means for controlling the feedback loop which modifies the frequency modulation information signals. The final output signals may be taken from the output of the feedback loop through a low-pass filter. If desired, an equalizing filter may also be interposed between the output of the feedback loop and the final low-pass filter.

Frequency demodulator for noise threshold extension

This paper presents experimental evaluation of the performance of more than 25 production units of a 100 A, DC to 100 kHz transconductance amplifier. In addition to the stability, uncertainty, distortion, and frequency response, experimental results seem to indicate that the output impedance may be closely modeled by a parallel combination of a resistor and a capacitor in series with a resistor. This model is then used to estimate, and to correct for, the effect of load inductance on high-frequency, high-current measurements.

Donald T. Hess

Papers

Communication Circuits: Analysis and Design

Phase measurement, traceability, and verification theory and practice

Circuit techniques for use in a digital phase-angle generator

Frequency demodulator for noise threshold extension

Evaluation of 100 ampere, 100 kHz transconductance amplifiers