Abstract
D.Ing.
In the field of power electronics, the relentless demand for higher efficiencies, lower costs and
ever-decreasing volume and profile have driven the development of many innovative
technologies. Planarization and hybridization have become a substantial part of present system
integration methodology. With the subsequent size reduction, the effects of layout and
component parasitics are becoming vital issues in the development of innovative structures.
The component ‘parasitics’ can be considered dimensional effects of the component structure
that are not considered during the design process. The concept of electromagnetic integration is
aimed at the utilization and modification of these dimensional effects. This leads to an integrated
structure that fulfills multiple electromagnetic functions with the potential for improved power
density, efficiency and reliability.
In this dissertation, a family of electromagnetically integrated passives is presented. The
related electromagnetic modeling and design approach of these complex electromagnetic
structures is presented through a case study of L-L-C-T structures. The development of a
sufficiently accurate, yet simplified electromagnetic model for design purposes is presented for
the case study. With the electromagnetic model as basis, a comprehensive electromagnetic loss
model is created.
The electromagnetic design and loss models are combined into a design evaluation program.
The graphical output of this design evaluation program allows for rapid selection of improved
designs based on external cost criteria. This led to numerous insights into the relationships
between the design variables. Through modification of the program, some fundamental limits of
the integration approach are addressed. A case study design for a 1MHz, 500W dc-dc converter
was considered to evaluate the design program.
To assess the accuracy of the electromagnetic modeling, three L-L-C-T prototypes are
constructed and experimentally tested. The construction process presented improved power
density by 80% over previous processes. The electromagnetic component parameters for three
prototypes were within 10% of the required design values, while the electromagnetic loss model
estimations were within measurement error. The design evaluation program was enlisted in the
design of two of these prototypes. This resulted in a 100% further improvement in power density
(480W/in3 or 29.3W/cm3) compared to the original prototype without a loss in efficiency.