Many people at the HEPHY [1] and in the CMS Collaboration directly or indirectly contributed to the work described within this thesis.
First of all, I am indebted to DI Manfred Pernicka who is in charge of the Electronics II Group at the HEPHY. He constantly supported and advised me not only in electronic matters, but also e.g. in cross-country skiing. I also want to thank Doz. Manfred Krammer, head of the Semiconductor Detector Group at HEPHY, for sharing his knowledge about silicon detectors, the cooperative construction of detector modules and for advising this thesis. I am very grateful to my advisor Prof. Wolfgang Fallmann at the Vienna University of Technology, who also taught me the basics of semiconductors.
Furthermore, I want to acknowledge the prosperous teamwork with my colleague Thomas Bauer, who is an expert in optoelectronics. I would also like to thank Helmut Steininger and Siegfried Schmid of the Electronics II Group, who made the design and layout of numerous electronic modules, and Josef Pirker, who is extraordinarily talented in soldering almost invisible components. I want to express my thanks to our project leader Dr. Josef Hrubec for his support, to Dr. Rudi Wedenig and Margit Oberegger of the Semiconductor Detector Group for their professional skills in wire-bonding, and to Rudolf Eitelberger and Roland Stark of the Mechanics Workshop for their constructions.
Moreover, I want to emphasize the selfless support of Dr. Kurt Gabathuler and Dr. Dieter Renker
with the 
and 
beamlines at PSI [65] and the help of
Dr. Jonathan Fulcher of IC [75] with the single event upset measurements.
I owe many thanks to the participants in the beam tests at PSI for the productive collaboration,
to Prof. Geoff Hall at IC and Prof. Gigi Rolandi at CERN for promoting our tests
and for ``authorizing'' this thesis,
to Dr. Francois Vasey and his colleagues of the CMS Tracker Optical Links group [72]
for their continuous support with optoelectronics
and to Prof. Wolfgang Lang of IMP [68] for providing the superconducting magnet.
Last but not least I am very grateful to my girlfriend Michaela Liebhart for her patience while I was working on this thesis and for proofreading. This task was also performed by my parents Hedy and Friedrich Friedl, whom I wish to express my big thanks also for their mental support and interest in my work.