Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Jan. 13, 2009). PDF text: ix, 93 p. : ill. ; 884 KB. UMI publication number: AAT 3315324. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--Ohio University, November, 1993. / Title from PDF t.p.

Thesis (Ph.D.)--University of Edinburgh, 1996.

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf iii).

Thesis (Ph. D.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 115-122).

Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 118-127).

Thesis (Ph.D.)--City University of Hong Kong, 2009. / "Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 105-111)

With the increasing system clock, a clock circuit will cause an amount of electromagnetic interference. To reduce EMI of the products, various EMI strategies have been developed. In the thesis, we study the suppression of electromagnetic interference of a clock circuit by using the spread spectrum technique. The basic idea of the spread spectrum is to slightly modulate the frequency of the clock signal and the energy of the signal will be dispersed to a controllable range to reduce the peak energy of each harmonic wave in the spectrum, and the products can pass the electromagnetic compatibility test more easily. We obtain the attenuation factor of spread spectrum from the theoretical derivation, including modulation index and modulation profiles. From the numerical simulation, we verify that spread spectrum technique can suppress the peak energy. We propose the attenuation formulas which can control the attenuation of every frequency point. To verify our findings, we use a spread spectrum clock generator from market to perform measurement. The trapezoidal waveform can be used to represent a clock circuit. Its waveform includes rise time and duty cycle. We will discuss the influence of rise time and duty cycle on the spread spectrum technique. Shorter rise time will cause high order harmonics in the high speed clock circuit. We verify that spread spectrum technique can suppress high order harmonics from both the simulation and experiment. Because every harmonic can be suppressed, the spread spectrum technique has the good suppression effect for the whole system.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / According to the advantages of chaotic analog sequences and chaotic binary sequences, this paper proposes a method generating chaotic binary spread-spectrum sequence by multilevel quantifying. This paper proved that even correlation and odd correlation between such sequences of length N are all Gaussian distributed with mean 0 and variance N, the even of mean-square cross-correlation is N, and the variance of mean-square cross-correlation is 2N. The method can increase the number of chaotic sequences, made the spread-spectrum system more secure. The theoretical analyses and the results of simulation show that the performance of such sequence general is as same as traditional spread-spectrum sequence, its number is very large, and can be used in CDMA in future.

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