In high-frequency circuit design, performance is often limited by the quality
of the passive components available for a particular process. Specifically, spiral
inductors can be a major bottle-neck for Voltage-Controlled Oscillators (VCOs),
Low-Noise Amplifiers (LNAs), mixers, etc. For designers to correctly optimize a circuit
using a spiral inductor, several frequency-domain characteristics must be known
including the quality factor (Q), total inductance, and the self-resonant frequency.
This information can be difficult to predict for spirals built on lossy silicon substrates
because of the complicated frequency-dependent loss mechanisms present.
The first part of this research addresses the need for a scalable, predictive
model for obtaining the frequency domain behavior of spiral inductors on lossy
silicon substrates. The technique is based on the Partial Element Equivalent Circuit
(PEEC) method and is a flexible approach to modelling spiral inductors. The basic
PEEC technique is also enhanced to efficiently include the frequency dependent
eddy-currents in the lossy substrate through a new complex-image method. This
enhanced PEEC approach includes all of the major non-ideal effects including the
conductor-skin and proximity effects, as well as the substrate-skin effect. The
approach is applied to octagonal spiral inductors and comparisons with measurements
are presented.
To complement the scalable enhanced-PEEC model, a new wide-band compact
equivalent circuit model is presented which is suitable for time-domain simulations.
This model achieves wide-band accuracy through the use of "transformer-loops"
to model losses caused by the magnetic field. A fast extraction technique
based on a least squares fitting procedure is also described. Results are presented
for a transformer-loop compact model extracted from measurements.
The combination of an accurate scalable model and a wide-band compact
equivalent-circuit model provides a complete modelling methodology for spiral inductors
on lossy silicon. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31638 |
| Date | 22 November 2002 |
| Creators | Melendy, Daniel |
| Contributors | Weisshaar, Andreas |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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