This work presents a design methodology for pattern reconfigurable antennas in automotive applications. Channel simulation is used to identify the relevant beam directions prior to the design of the antenna. Based on this knowledge several reconfigurable multiple antenna systems are designed. These antennas are evaluated by the channel capacity calculation from virtual and real-world test drives. An increase of the channel capacity by a factor of 2 compared to a conventional system is observed.

This work explores short-range millimeter wave radar systems, with emphasis on miniaturization and overall system cost reduction. The designing and implementation processes, starting from the system level design considerations and characterization of the individual components to final implementation of the proposed architecture are described briefly. Several D-band radar systems are developed and their functionality and performances are demonstrated.

In dieser Arbeit werden Methoden zur Erzeugung von TE₀- und TM₀-Oberflächenwellen für die Anwendung in mmW-Leckwellenantennen nach dem holografischen Prinzip vorgestellt und untersucht. Ziel ist dabei, die Integrierbarkeit der Oberflächenwellenerzeuger in mmW-Systeme zu vereinfachen und gleichzeitig die Abstrahleigenschaften der Leckwellenantennen zu verbessern. In this work new methods for the generation of TE₀ and TM₀ surface waves for mmW leaky wave antennas using the holographic principle are presented and evaluated. The main goal is to simplify the integrability of the surface wave launcher into mmW systems and at the same time improve the radiation characteristics of the leaky wave antenna.

Measurement at millimeter-wave frequencies are prone to parasitic effects which distort the overall results. Especially the use of RF probes introduces unknown distortions, even after the measurement setup is calibrated. This works investigates these distortions based on electromagnetic field simulations of integrated circuits in conjunction with models of the used RF probes. This allows to comprehend the observed distortions and successfully resolve the root of the distortions.

Die vorliegende Arbeit beschäftigt sich mit der Entwicklung von Breitbandverstärkern mit einstellbarem Gewinn. Es werden verschiedene Schaltungskonzepte zur Einstellung des Verstärkergewinns untersucht, und sowohl kompakte als auch verteilte Verstärkerschaltungen in SiGe BiCMOS Technologien hergestellt. Ein weiterer Schwerpunkt der Arbeit ist die Modellierung von verteilten Verstärkern mithilfe von Bildparametern, die eine analytische und kompakte Beschreibung ermöglichen. The present work deals with the development of broadband amplifiers with adjustable gain. Different circuit topologies for gain control are investigated, and several compact and distributed amplifiers are fabricated in SiGe BiCMOS technologies. Another key aspect of the work is the modeling of distributed amplifiers by means of image parameters, which enable an analytical and compact description.

Current automotive radar sensors prove to be a weather robust and low-cost solution, but are suffering from low resolution and are not capable of classifying detected targets. However, for future applications like autonomous driving, such features are becoming ever increasingly important. On the basis of successful state-of-the-art applications, this work presents the first in-depth analysis and ground-breaking, novel results of polarimetric millimeter wave radars for automotive applications.

This work presents a low temperature co-fired ceramic (LTCC) technology based system-in-package (SiP) operating beyond 100 GHz. The SiP encloses a semiconductor transceiver chip in a pea-sized LTCC package. The SiP is efficient and robust in terms of its electrical, thermal and mechanical characteristics. Moreover, it is low-cost and requires only standard manufacturing and assembly techniques. Finally, two fully-integrated 122 GHz radar sensors are demonstrated in LTCC technology.