Microwave-assisted alkaline hydrolysis of PET can be 20 times faster and at lower temperatures. This work presents a novel industrial microwave applicator at 2.45 GHz with homogeneous distribution to support this reaction, which allows an efficient and continuous operation. In addition, an innovative dielectric and calorimetric measurements setup is presented. Furthermore, the modelling of the reaction kinetics based on the measured dielectric parameters is presented.

High energy demand is one reason for high costs of carbon fibers. One option to decrease them is to use microwave heating instead of conventional heating. In this work, steps towards a microwave assisted process during the stabilization phase are presented. In-situ dielectric measurements are performed and a reaction kinetics model is setup in connection to the dielectric loss. This allows to calculate a stabilization degree and fiber temperatures leading to a basic process understanding.

This work presents the development of a new sub-THz source for the generation of trains of coherent high-power ultra-short pulses at 263 GHz via passive mode-locking of two coupled helical gyro-TWTs. For the first time, it is shown that the operation of such passive mode-locked helical gyro-TWTs in the hard excitation regime is of particular importance to reach the optimal coherency of the generated pulses. This could be of particular interest for some new time-domain DNP-NMR methods.

Ein Gyrotron wird in magnetisch eingeschlossenen Plasmaexperimenten für Heizung, Stromtrieb, Plasmastabilisierung und Plasmadiagnostik verwendet. In dieser Arbeit wird der erste Entwurf und Bau eines Mehrfrequenz-/Mehrzweck Pre-Prototyp Gyrotrons in koaxialer Technologie vorgestellt, das bei (136)/170/204 GHz mit einer Ausgangsleistung von 2 MW arbeitet. Dies ist der erste Schritt zum Betrieb bei Frequenzen bis zu 240 GHz unter Verwendung der Koaxialhohlraum-Gyrotrontechnologie. - A gyrotron is used in magnetically confined plasma experiments for heating, current drive, plasma stabilization and plasma diagnostics. This work presents the first design and construction of a multi-frequency / multi-purpose coaxial-cavity pre-prototype gyrotron operating at (136)/170/204 GHz with an output power of 2 MW. It is the first step towards operating frequencies up to 240 GHz using the coaxial-cavity gyrotron technology.

Magnetic confinement fusion relies on plasma heating and plasma control using gyrotron oscillators providing at megawatt power levels. The operational reliability decreases when operating at the performance limits due to increasing parasitic mode activity. This work demonstrates for the first time the automated, fast recovery of nominal gyrotron operation during a pulse by exploiting the hysteretic gyrotron behaviour after a mode switch being in use at the Wendelstein 7-X ECRH facility.

Foreword by Dr. Asad Madni, C. Eng., Fellow IEEE, Fellow IEE Learn the fundamentals of RF and microwave electronics visually, using many thoroughly tested, practical examples RF and microwave technology are essential throughout industry and to a world of new applications-in wireless communications, in Direct Broadcast TV, in Global Positioning System (GPS), in healthcare, medical and many other sciences. Whether you're seeking to strengthen your skills or enter the field for the first time, Radio Frequency and Microwave Electronics Illustrated is the fastest way to master every key measurement, electronic, and design principle you need to be effective. Dr. Matthew Radmanesh uses easy mathematics and a highly graphical approach with scores of examples to bring about a total comprehension of the subject. Along the way, he clearly introduces everything from wave propagation to impedance matching in transmission line circuits, microwave linear amplifiers to hard-core nonlinear active circuit design in Microwave Integrated Circuits (MICs). Coverage includes: A scientific framework for learning RF and microwaves easily and effectively Fundamental RF and microwave concepts and their applications The characterization of two-port networks at RF and microwaves using S-parameters Use of the Smith Chart to simplify analysis of complex design problems Key design considerations for microwave amplifiers: stability, gain, and noise Workable considerations in the design of practical active circuits: amplifiers, oscillators, frequency converters, control circuits RF and Microwave Integrated Circuits (MICs) Novel use of "live math" in circuit analysis and design Dr. Radmanesh has drawn upon his many years of practical experience in the microwave industry and educational arena to introduce an exceptionally wide range of practical concepts and design methodology and techniques in the most comprehensible fashion. Applications include small-signal, narrow-band, low noise, broadband and multistage transistor amplifiers; large signal/high power amplifiers; microwave transistor oscillators, negative-resistance circuits, microwave mixers, rectifiers and detectors, switches, phase shifters and attenuators. The book is intended to provide a workable knowledge and intuitive understanding of RF and microwave electronic circuit design. Radio Frequency and Microwave Electronics Illustrated includes a comprehensive glossary, plus appendices covering key symbols, physical constants, mathematical identities/formulas, classical laws of electricity and magnetism, Computer-Aided-Design (CAD) examples and more. About the Web Site The accompanying web site has an "E-Book" containing actual design examples and methodology from the text, in Microsoft Excel environment, where files can easily be manipulated with fresh data for a new design.