@phdthesis{Ruecker2017, author = {R{\"u}cker, Johannes}, title = {Automatisierte Detektion und Extraktion von Elektroschrott-Komponenten mit Methoden der Bildverarbeitung und des maschinellen Lernens im Hinblick auf Tantal-Recycling}, school = {Technische Hochschule Aschaffenburg}, year = {2017}, subject = {Elektronikschrott}, language = {de} } @phdthesis{Woelfel2018, author = {W{\"o}lfel, Maximilian}, title = {Hochintegriertes hardwaregest{\"u}tztes Messverfahren zur Untersuchung von fehlerbehafteten {\"U}bertragungskan{\"a}len in TETRA-Objektfunkversorgungen}, school = {Technische Hochschule Aschaffenburg}, year = {2018}, subject = {TETRA, Telekommunikation}, language = {de} } @inproceedings{ProbstHitzingerBochtleretal.2021, author = {Probst, Anne-Catherine and Hitzinger, Hans and Bochtler, Ulrich and W{\"o}lfel, Maximilian and Schmitt, Christoph}, title = {High Frequency Power Amplifier for Wideband Wireless Communication Systems}, series = {Proceedings of the 2021 Kleinheubach Conference}, volume = {2021}, booktitle = {Proceedings of the 2021 Kleinheubach Conference}, editor = {U.R.S.I. Landesausschuss in Deutschland e.V. 2021,}, doi = {10.23919/IEEECONF54431.2021.9598443}, pages = {4}, year = {2021}, abstract = {Increasing data transmission rates and bandwidth both belong to the challenges of the development of high-performance wireless communication systems. Multi-channel communication systems commonly use several narrowband power amplifiers each one for a single communication channel. Lossy couplers are needed both to separate the different channels from each other at the amplifiers input and to combine the amplified signals on each channel at the output. This approach depicts a poor efficiency and is limited to a few number of channels since each channel duplication involves 3 dB losses due to couplers. Alternatively, broadband radio frequency power amplifiers ensuring the simultaneous transmission of several carriers on a wide frequency range contribute to increase the cost and resource efficiency of transceivers in wireless communication systems. Gain flatness, a high output power, and low power levels of second and third order harmonics are required on the whole operating frequency range of the power amplifier in multi-carrier communication systems since overtones will degrade the quality of the communication. The present work investigates the performances of a broadband push-pull power amplifier based on LDMOS transistors, the input matching network using a 8:1 transmission line transformer. For the first time investigations on harmonic distortions of the amplified signal when using a transformer with 8:1 impedance transformation ratio are presented. Characterisation of the power amplifiers performances is focused on gain flatness, output power, harmonic distortions and efficiency at 110 W.}, subject = {Hochfrequenzverst{\"a}rker}, language = {en} }