@misc{HeiderBochtler2016, author = {Heider, Michael and Bochtler, Ulrich}, title = {Trennung technischer Keramiken mit elektrischen Verfahren zur effizienteren Weiterverarbeitung und Wertstoffr{\"u}ckgewinnung}, year = {2016}, abstract = {Poster}, subject = {Abfallwirtschaft}, language = {de} } @misc{WangRueckerHeschetal.2016, author = {Wang, Jiaxi and R{\"u}cker, Johannes and Hesch, Heinz-Xaver and Bochtler, Ulrich and Klar, Peter J.}, title = {Analyse von elektronischen Altger{\"a}ten im Hinblick auf verbesserte Recyclingverfahren}, year = {2016}, abstract = {Poster}, subject = {Abfallwirtschaft}, language = {de} } @inproceedings{RueckerHeschBochtleretal.2016, author = {R{\"u}cker, Johannes and Hesch, Heinz-Xaver and Bochtler, Ulrich and Klar, Peter J.}, title = {Automated Segmentation of Electronic Components on Waste Printed Circuit Boards}, series = {7th Sensor-Based Sorting \& Control 2016}, booktitle = {7th Sensor-Based Sorting \& Control 2016}, editor = {Pretz, Thomas and Wotruba, Hermann}, publisher = {Shaker}, address = {Herzogenrath}, isbn = {978-3-8440-4323-5}, pages = {179 -- 185}, year = {2016}, subject = {Demontage}, language = {en} } @inproceedings{RueckerHeschBochtleretal.2016, author = {R{\"u}cker, Johannes and Hesch, Heinz-Xaver and Bochtler, Ulrich and Klar, Peter J.}, title = {An empirical approach for more effective recycling of electronic components in WEEE}, series = {7th Sensor-Based Sorting \& Control 2016}, booktitle = {7th Sensor-Based Sorting \& Control 2016}, editor = {Pretz, Thomas and Wotruba, Hermann}, publisher = {Shaker}, address = {Aachen}, isbn = {9783844043235}, pages = {249 -- 258}, year = {2016}, subject = {Elektronikschrott}, language = {en} } @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} } @article{KoehlerWoelfelCibaetal.2018, author = {K{\"o}hler, Tim and W{\"o}lfel, Maximilian and Ciba, Manuel and Bochtler, Ulrich and Thielemann, Christiane}, title = {Terrestrial Trunked Radio (TETRA) exposure of neuronal in vitro networks}, series = {Environmental Research}, volume = {2018}, journal = {Environmental Research}, number = {162}, doi = {10.1016/j.envres.2017.12.007}, pages = {1 -- 7}, year = {2018}, abstract = {Terrestrial Trunked Radio (TETRA) is a worldwide common mobile communication standard, used by authorities and organizations with security tasks. Previous studies reported on health effects of TETRA, with focus on the specific pulse frequency of 17.64 Hz, which affects calcium efflux in neuronal cells. Likewise among others, it was reported that TETRA affects heart rate variability, neurophysiology and leads to headaches. In contrast, other studies conclude that TETRA does not affect calcium efflux of cells and has no effect on people's health. In the present study we examine whether TETRA short- and long-term exposure could affect the electrophysiology of neuronal in vitro networks. Experiments were performed with a carrier frequency of 395 MHz, a pulse frequency of 17.64 Hz and a differential quaternary phase-shift keying (π/4 DQPSK) modulation. Specific absorption rates (SAR) of 1.17 W/kg and 2.21 W/kg were applied. In conclusion, the present results do not indicate any effect of TETRA exposure on electrophysiology of neuronal in vitro networks, neither for short-term nor long-term exposure. This applies to the examined parameters spike rate, burst rate, burst duration and network synchrony.}, subject = {Neuronales Netz}, language = {en} } @article{OsterDausErbesetal.2016, author = {Oster, Stefan and Daus, Andreas and Erbes, Christian and Goldhammer, Michael and Bochtler, Ulrich and Thielemann, Christiane}, title = {Long-term electromagnetic exposure of developing neuronal networks: A flexible experimental setup}, series = {Bioelectromagnetics}, volume = {2016}, journal = {Bioelectromagnetics}, number = {37}, doi = {10.1002/bem.21974}, pages = {264 -- 278}, year = {2016}, abstract = {Neuronal networks in vitro are considered one of the most promising targets of research to assess potential electromagnetic field induced effects on neuronal functionality. A few exposure studies revealed there is currently no evidence of any adverse health effects caused by weak electromagnetic fields. Nevertheless, some published results are inconsistent. Particularly, doubts have been raised regarding possible athermal biological effects in the young brain during neuronal development. Therefore, we developed and characterized a flexible experimental setup based on a transverse electromagnetic waveguide, allowing controlled, reproducible exposure of developing neuronal networks in vitro. Measurement of S-parameters confirmed very good performance of the Stripline in the band of 800-1000 MHz. Simulations suggested a flexible positioning of cell culture dishes throughout a large exposure area, as specific absorption rate values were quite independent of their position (361.7 ± 11.4 mW/kg) at 1 W, 900 MHz. During exposure, thermal drift inside cellular medium did not exceed 0.1 K. Embryonic rat cortical neurons were cultivated on microelectrode array chips to non-invasively assess electrophysiological properties of electrogenic networks. Measurements were taken for several weeks, which attest to the experimental setup being a reliable system for long-term studies on developing neuronal tissue.}, subject = {Neuronales Netz}, language = {en} } @inproceedings{DausOsterErbesetal.2013, author = {Daus, Andreas and Oster, Stefan and Erbes, Christian and Goldhammer, Michael and Bochtler, Ulrich and Thielemann, Christiane}, title = {Electromagnetic exposure of neuronal networks on microelectrode arrays}, series = {U.R.S.I. Landesausschuss in der Bundesrepublik Deutschland e.V., Kleinheubacher Tagung, Miltenberg, Abstracts}, booktitle = {U.R.S.I. Landesausschuss in der Bundesrepublik Deutschland e.V., Kleinheubacher Tagung, Miltenberg, Abstracts}, pages = {29 -- 30}, year = {2013}, subject = {Neuronales Netz}, language = {en} } @inproceedings{OsterDausGoldhammeretal.2013, author = {Oster, Stefan and Daus, Andreas and Goldhammer, Michael and Bochtler, Ulrich and Thielemann, Christiane}, title = {A Flexible RF Exposure Setup for Long-term Electrophysiological Investigations on Biological Samples in Vitro}, series = {Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Schweden}, booktitle = {Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Schweden}, year = {2013}, subject = {Neuronales Netz}, language = {en} } @inproceedings{GoldhammerDausThielemannetal.2009, author = {Goldhammer, Michael and Daus, Andreas and Thielemann, Christiane and Bochtler, Ulrich}, title = {Flexible measurement setup for electromagnetic exposition of biological samples}, series = {BioEM 2009, Davos, Switzerland}, booktitle = {BioEM 2009, Davos, Switzerland}, year = {2009}, subject = {Elektromagnetische Strahlung}, language = {en} } @inproceedings{DausGoldhammerBochtleretal.2009, author = {Daus, Andreas and Goldhammer, Michael and Bochtler, Ulrich and Thielemann, Christiane}, title = {Electromagnetic exposition of neuronal networks in vitro}, series = {Radiofrequency fields and health}, booktitle = {Radiofrequency fields and health}, organization = {Forschungsgemeinschaft Funk, Stuttgart}, year = {2009}, subject = {Neuronales Netz}, language = {en} } @inproceedings{DausGoldhammerBochtleretal.2010, author = {Daus, Andreas and Goldhammer, Michael and Bochtler, Ulrich and Thielemann, Christiane}, title = {A new approach for the investigation of long-term effects of RF radiation on cells}, series = {28th Progress In Electromagnetics Research Symposium 2010, Cambridge}, booktitle = {28th Progress In Electromagnetics Research Symposium 2010, Cambridge}, year = {2010}, subject = {Hochfrequenz}, language = {en} } @inproceedings{KoehlerWoelfelBochtleretal.2016, author = {K{\"o}hler, Tim and W{\"o}lfel, Maximilian and Bochtler, Ulrich and Thielemann, Christiane}, title = {TETRA specific long-term exposure of neuronal in vitro networks}, series = {BioEM2016}, booktitle = {BioEM2016}, year = {2016}, subject = {Neuronales Netz}, language = {en} } @inproceedings{NeumaierProbstWoelfeletal.2025, author = {Neumaier, Marcel and Probst, Anne-Catherine and W{\"o}lfel, Maximilian and Bochtler, Ulrich}, title = {Performance Analysis in a Digital TETRA-Simulcast System}, series = {2025 16th German Microwave Conference (GeMiC)}, booktitle = {2025 16th German Microwave Conference (GeMiC)}, year = {2025}, abstract = {In radio communication of mission-critical services, resilient solutions are strongly required to account for public safety. Additionally to the cellular network based on the professional mobile radio European standard TETRA, a digital TETRA-simulcast system is proposed as a redundant network to ensure area coverage in case of base station failure caused e.g. by disasters. This paper presents a preliminary study about network planning of a frequency-efficient digital TETRA-simulcast system to be physically deployed in a hilly region of Germany. Coverage as well as ray tracing analysis and channel modeling were performed by simulations and prove to be helpful tools for the systematic optimization of system performances, especially with regard to the control of intersymbol interference in overlapping zones.}, subject = {TETRA, Telekommunikation}, language = {en} } @inproceedings{ProbstNeumaierHufgardetal.2025, author = {Probst, Anne-Catherine and Neumaier, Marcel and Hufgard, Christopher and W{\"o}lfel, Maximilian and Schmitt, Christoph and Bochtler, Ulrich}, title = {Network Planning a Digital TETRA-Simulcast-System}, series = {Kleinheubacher Tagung, Miltenberg, 23.09.2025 - 25.09.2025}, booktitle = {Kleinheubacher Tagung, Miltenberg, 23.09.2025 - 25.09.2025}, year = {2025}, subject = {TETRA, Telekommunikation}, language = {en} }