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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Extending the measurement range of an optical surface profiler.

Cochran, Eugene Rowland, III. January 1988 (has links)
This dissertation investigates a method for extending the measurement range of an optical surface profiling instrument. The instrument examined in these experiments is a computer-controlled phase-modulated interference microscope. Because of its ability to measure surfaces with a high degree of vertical resolution as well as excellent lateral resolution, this instrument is one of the most favorable candidates for determining the microtopography of optical surfaces. However, the data acquired by the instrument are restricted to a finite lateral and vertical range. To overcome this restriction, the feasibility of a new testing technique is explored. By overlapping a series of collinear profiles the limited field of view of this instrument can be increased and profiles that contain longer surface wavelengths can be examined. This dissertation also presents a method to augment both the vertical and horizontal dynamic range of the surface profiler by combining multiple subapertures and two-wavelength techniques. The theory, algorithms, error sources, and limitations encountered when concatenating a number of profiles are presented. In particular, the effects of accumulated piston and tilt errors on a measurement are explored. Some practical considerations for implementation and integration into an existing system are presented. Experimental findings and results of Monte Carlo simulations are also studied to explain the effects of random noise, lateral position errors, and defocus across the CCD array on measurement results. These results indicate the extent to which the field of view of the profiler may be augmented. A review of current methods of measuring surface topography is included, to provide for a more coherent text, along with a summary of pertinent measurement parameters for surface characterization. This work concludes with recommendations for future work that would make subaperture-testing techniques more reliable for measuring the microsurface structure of a material over an extended region.
22

Analysis domain truncation of interconnections in multilayer packaging structures

Garg, Nitin Kumar, 1967- January 1989 (has links)
Interconnect lines, which connect components on a chip, can exhibit transmission line properties. Several factors like decrease in size of components, and decrease in spacing between interconnect lines, have contributed to the increase in importance of interconnect lines. A circuit-analysis approach that does not include the effect of these lines may be useless for highly dense chips. The presence of an active line does not require the analysis of all the other lines in a transmission-line system. In this thesis, a numerical experimental approach based on several industry-typical geometries is used to discuss analysis domain truncation of parallel conductors lying on a horizontal plane. It is found that "The maximum analysis domain between parallel conductors lying on a horizontal plane can be deduced from the analysis of the case of several similar, and parallel conductors of smallest possible width lying on a horizontal plane." UAC (University of Arizona Capacitance Calculator) is used as the TEM parameter extractor, while UACSL (University of Arizona Coupled Line Simulator With Linear Terminations) is used to calculate the voltages on the transmission lines.
23

Investigation of cable emissions within a screened room environment

Goodwin, Stephen January 1989 (has links)
No description available.
24

Modelling RF interference effects in integrated circuits

Whyman, Neil L. January 2003 (has links)
No description available.
25

New techniques for the measurement of radiated emissions in a screened room for frequencies up to 200MHz

Dawson, Linda January 1989 (has links)
No description available.
26

Burst-by-burst adaptive multiuser detection CDMA techniques

Kuan, Ee Lin January 1999 (has links)
No description available.
27

Quantitative and automatic analysis of interferometric fringe data using carrier fringe and FFT techniques

Quan, C. January 1992 (has links)
No description available.
28

Development of inductively coupled plasma mass spectrometry (ICP MS) analysis of noble metals in the environment

Simpson, Lorna A. January 2002 (has links)
No description available.
29

Algorithms and structures for spatial and temporal equalisation in TDMA mobile communications

Wanchaleam, Pora January 2000 (has links)
No description available.
30

Optimisation of multi carrier data transmission systems in the presence of nonlinearity

Goh, Tracey Su Leen January 2003 (has links)
No description available.

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