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Time domain characterization of interconnect discontinuities

The purpose of this study is to develop experimental techniques to
characterize typical interconnect discontinuities, including bends, steps, T
junctions, vias and pads, which are the most commonly encountered
interconnections in high speed digital integrated circuits, hybrid and
monolithic microwave circuits and electronic packages. The time domain
reflection response of these elements is used to classify the interconnect
discontinuities as distributed discontinuity elements or as lumped elements
depending upon the reflected waveform. For the cases of general distributed
discontinuities including bends, steps and T junctions, the distributed
equivalent circuit model is characterized by the time dependent impedance
profile which is extracted from the time domain reflection measurements. By
using known inverse scattering techniques implemented in terms of a new
algorithm based on the transfer scattering matrix method of incremental
uniform sections, this nonuniform impedance profile is extracted and is used
to construct distributed element circuit models to represent the interconnect
discontinuities. A circuit model consisting of lumped/distributed elements,
is also developed for the interconnect discontinuities which is intended to
combine the accuracy of the distributed model with the simulation efficiency
of the lumped models. This hybrid mode reduces computer simulation time
when used as a net list for general purpose circuit simulators, such as SPICE.
For the case of discontinuities modelled as lumped elements, such as vias and
wiring pads, closed form equations based on the transfer scattering matrix
solution are derived and used to extract the lumped electrical parameters of
these elements from the time domain reflection waveform. All of these
lumped, distributed and hybrid models are validated by comparing the time
domain simulation results with Time Domain Reflectrometer ( TDR )
measurements. A procedure for extracting the excess inductances and
capacitances associated with the general discontinuities from the synthesized
nonuniform impedance profile or the distributed model is also presented in
this report. These results for excess lumped inductances and capacitances
show close agreement with the published results for these structures which
are based on the electromagnetic computation of excess currents and charges
and frequency domain measurements. Finally, some typical cases
demonstrating the effects of interconnect discontinuities in high speed
clocking systems are presented and the procedure for reducing the reflections
and transmission noise voltage by chamfering the bends and junctions is
described. / Graduation date: 1992

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/36724
Date18 September 1991
CreatorsJong, Jyh-Ming
ContributorsTripathi, Vijai K.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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