TY - JOUR
AU - Riedl, Thomas
AU - Lindner, Jörg
ID - 34089
JF - Solid State Communications
KW - Materials Chemistry
KW - Condensed Matter Physics
KW - General Chemistry
SN - 0038-1098
TI - Applicability of molecular statics simulation to partial dislocations in GaAs
VL - 314-315
ER -
TY - CONF
AB - Novel analog-to-digital converter (ADC) architectures are motivated by the demand for rising sampling rates and effective number of bits (ENOB). The main limitation on ENOB in purely electrical ADCs lies in the relatively high jitter of oscillators, in the order of a few tens of fs for state-of-the-art components. When compared to the extremely low jitter obtained with best-in-class Ti:sapphire mode-locked lasers (MLL), in the attosecond range, it is apparent that a mixed electrical-optical architecture could significantly improve the converters' ENOB. We model and analyze the ENOB limitations arising from optical sources in optically enabled, spectrally sliced ADCs, after discussing the system architecture and implementation details. The phase noise of the optical carrier, serving for electro-optic signal transduction, is shown not to propagate to the reconstructed digitized signal and therefore not to represent a fundamental limit. The optical phase noise of the MLL used to generate reference tones for individual slices also does not fundamentally impact the converted signal, so long as it remains correlated among all the comb lines. On the other hand, the timing jitter of the MLL, as also reflected in its RF linewidth, is fundamentally limiting the ADC performance, since it is directly mapped as jitter to the converted signal. The hybrid nature of a photonically enabled, spectrally sliced ADC implies the utilization of a number of reduced bandwidth electrical ADCs to convert parallel slices, resulting in the propagation of jitter from the electrical oscillator supplying their clock. Due to the reduced sampling rate of the electrical ADCs, as compared to the overall system, the overall noise performance of the presented architecture is substantially improved with respect to a fully electrical ADC.
AU - Zazzi, Andrea
AU - Müller, Juliana
AU - Gudyriev, Sergiy
AU - Marin-Palomo, Pablo
AU - Fang, Dengyang
AU - Scheytt, Christoph
AU - Koos, Christian
AU - Witzens, Jeremy
ID - 24020
T2 - 21. ITG-Fachtagung Photonische Netze
TI - Mode-locked laser timing jitter limitation in optically enabled frequency-sliced ADCs
ER -
TY - JOUR
AB - The effect of phase noise introduced by optical sources in spectrally-sliced optically enabled DACs and ADCs is modeled and analyzed in detail. In both data converter architectures, a mode-locked laser is assumed to provide an optical comb whose lines are used to either synthesize or analyze individual spectral slices. While the optical phase noise of the central MLL line as well as of other optical carriers used in the analyzed system architectures have a minor impact on the system performance, the RF phase noise of the MLL fundamentally limits it. In particular, the corresponding jitter of the MLL pulse train is transferred almost one-to-one to the system-level timing jitter of the data converters. While MLL phase noise can in principle be tracked and removed by electronic signal processing, this results in electric oscillator phase noise replacing the MLL jitter and is not conducive in systems leveraging the ultra-low jitter of low-noise mode-locked lasers. Precise analytical models are derived and validated by detailed numerical simulations.
AU - Zazzi, Andrea
AU - Müller, Juliana
AU - Gudyriev, Sergiy
AU - Marin-Palomo, Pablo
AU - Fang, Dengyang
AU - Scheytt, Christoph
AU - Koos, Christian
AU - Witzens, Jeremy
ID - 24025
JF - Opt. Express
TI - Fundamental limitations of spectrally-sliced optically enabled data converters arising from MLL timing jitter
VL - 28
ER -
TY - CONF
AB - A 28 Gbps NRZ bang-bang clock and data recovery (CDR) chip for 100G PSM4 is presented. It exhibits an adaptable loop filter transfer function with independently tunable proportional and integral parameters. This allows to optimize the jitter transfer, jitter tolerance, and locking range of the CDR according to system requirements. The CDR represents a key component for a single-chip 8-channel electronic-photonic PSM4 transceiver. A CDR chip was manufactured in a 0.25 μm monolithic photonic BiCMOS technology. The core chip area is 0.51 mm 2 and it dissipates 330 mW from 2.5 V and 3.3 V power supplies.
AU - Iftekhar, Mohammed
AU - Gudyriev, Sergiy
AU - Scheytt, Christoph
ID - 24028
T2 - 2020 IEEE 20th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF)
TI - 28 Gbps Bang-Bang CDR for 100G PSM4 with Independently Tunable Proportional and Integral Parameters of the Loop Filter in 0.25 µm Photonic BiCMOS Technology
ER -
TY - CONF
AB - In this paper we present a new system concept for an optoelectronic wireless phased array system. Like in a conventional phased array system with optical carrier distribution, optical fibers are used to distribute the carrier from the basestation to the wireless frontends. However in contrast to prior concepts, we propose to use an optical IQ return path from the wireless frontends back to the basestation. Furthermore, we reuse the optical carrier signal for the IQ return path which allows to avoid local oscillator lasers in the wireless frontends and reduces the hardware effort significantly. The system concept allows to integrate all components of an optoelectronic wireless frontend in a single chip using silicon photonics technology.
AU - Kruse, Stephan
AU - Kress, Christian
AU - Scheytt, Christoph
AU - Kurz, Heiko G.
AU - Schneider, Thomas
ID - 24026
T2 - GeMiC 2020 - German Microwave Conference
TI - Analysis and Simulation of a Wireless Phased Array System with Optical Carrier Distribution and an Optical IQ Return Path
ER -
TY - JOUR
AU - Atorf, Bernhard
AU - Mühlenbernd, Holger
AU - Zentgraf, Thomas
AU - Kitzerow, Heinz-Siegfried
ID - 16301
IS - 6
JF - Optics Express
SN - 1094-4087
TI - All-optical switching of a dye-doped liquid crystal plasmonic metasurface
VL - 28
ER -
TY - CONF
AB - Recently it has been demonstrated that an optoelectronic phase-locked loop (OEPLL) using a mode-locked laser as a reference oscillator achieves significantly lower phase noise than conventional electronic frequency synthesizers. In this paper a concept for an OEPLL-based frequency synthesizer is presented and it is investigated how it can be used as a local oscillator (LO) for THz transceivers in order to improve the signal quality in THz wireless communications. The concept of the OEPLL is presented and it's measured phase noise is compared to the phase noise of a laboratory-grade electronic frequency synthesizer. The measured phase noise spectra of both synthesizers at 10 GHz are then used to model LO phase noise at 320 GHz. Based on models of generic zero-IF transmit and receive frontends, THz signals with different modulation formats and Baud rates are simulated at system level using the modeled LO phase noise for the two LO approaches. Finally, the results are compared.
AU - Scheytt, Christoph
AU - Wrana, Dominik
AU - Bahmanian, Meysam
AU - Kallfass, Ingmar
ID - 24024
T2 - 2020 Third International Workshop on Mobile Terahertz Systems (IWMTS)
TI - Ultra-Low Phase Noise Frequency Synthesis for THz Communications Using Optoelectronic PLLs
ER -
TY - CHAP
AU - Lankeit, Elisa
AU - Biehler, Rolf
ED - Hausberger, T.
ED - Bosch, M.
ED - Chelloughi, F.
ID - 35912
T2 - Proceedings of the Third Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2020, 12-19 September 2020)
TI - “I only know the absolute value function”–About students’ concept images and example spaces concerning continuity and differentiability
ER -
TY - CHAP
AU - Lankeit, Elisa
AU - Bauer, T.
AU - Biehler, Rolf
ED - Siller, H.-S.
ED - Weigel, W.
ED - Wörler, J. F.
ID - 35911
T2 - Beiträge zum Mathematikunterricht 2020
TI - Votingfragen in den Übungen zur Analysis – Wirkung verschiedener Einsatzszenarien
ER -
TY - GEN
AU - Caruso, Carina
ED - Zimmermann, Mirjam
ED - Lindler, Heike
ID - 35929
T2 - Das wissenschaftlich-religionspädagogische Lexikon im Internet
TI - Praxissemester
ER -
TY - JOUR
AU - Caruso, Carina
ID - 35935
JF - katholisch.de, Kolumne „Mein Religionsunterricht“.
TI - Der Weg zur Theologie-Professur ist hart – gerade für Religionslehrer!
ER -
TY - JOUR
AU - Schwabl, Franziska
ID - 35968
JF - bwp@Berufs-und Wirtschaftspädagogik – online
TI - Fotografien als Zugang zur Lebenswelt Jugendlicher. Eine Analyse der digitalen Inszenierungspraktiken Jugendlicher im berufsschulischen Übergangssystem.
VL - 38
ER -
TY - JOUR
AU - Lünne, Steffen
AU - Schnell, Susanne
AU - Biehler, Rolf
ID - 35701
IS - 5
JF - European Journal of Teacher Education
KW - Education
SN - 0261-9768
TI - Motivation of out-of-field teachers for participating in professional development courses in mathematics
VL - 44
ER -
TY - CHAP
AU - Barzel, Bärbel
AU - Biehler, Rolf
ED - Zehetmeier, Stefan
ED - Potari, Despina
ED - Ribeiro, Miguel
ID - 35808
T2 - Professional development and knowledge of mathematics teachers
TI - Theory-Based Design of Professional Development for Upper Secondary Teachers–Focusing on the Content-Specific Use of Digital Tools
ER -
TY - CHAP
AU - Biehler, Rolf
AU - Durand-Guerrier, Viviane
ED - Hausberger, T.
ED - Bosch, M.
ED - Chelloughi, F.
ID - 35811
KW - Number Theory
KW - Algebra
KW - Discrete Mathematics
KW - Logic
KW - Research in University Mathematics Edcuation
T2 - Proceedings of the Third Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2020, 12-19 September 2020)
TI - University Mathematics Didactic Research on Number Theory, Algebra, Discrete Mathematics, Logic
ER -
TY - CHAP
AU - Budde, Lea
AU - Frischemeier, Daniel
AU - Biehler, Rolf
AU - Fleischer, Yannik
AU - Gerstenberger, Dietrich
AU - Podworny, Susanne
AU - Schulte, Carsten
ED - Arnold, P.
ID - 35821
T2 - New Skills in the Changing World of Statistics Education: Proceedings of the Roundtable conference of the International Association for Statistical Education (IASE), July 2020
TI - Data Science Education in Secondary School: How to Develop Statistical Reasoning When Exploring Data Using CODAP
ER -
TY - CHAP
AU - Biehler, Rolf
AU - Kempen, Leander
AU - Paravicini, Walther
ED - Siller, H.-S.
ED - Weigel, W.
ED - Wörler, J. F.
ID - 35819
T2 - Beiträge zum Mathematikunterricht 2020
TI - Hochschuldidaktik Mathematik: Fachbezogenes Design und empirische Studien
ER -
TY - JOUR
AB - AbstractThe derivative concept plays a major role in economics. However, its use in economics is very heterogeneous, sometimes inconsistent, and contradicts students’ prior knowledge from school. This applies in particular to the common economic interpretation of the derivative as the amount of change while increasing the production by one unit. Hence, in calculus courses for economics students, learners should acquire an understanding of the derivative that is mathematically acceptable and connected to their prior knowledge, but which also takes into account its practical use in economics. In this paper we first develop a theoretical model describing such an understanding of the derivative for economics students. We then present an exploratory study investigating the extent to which economics students have such an understanding after their calculus course. The results indicate that many of them might not have acquired this kind of understanding, in particular concerning the common economic interpretation of the derivative. The study furthermore yields possible gaps in students’ understanding and possible misconceptions.
AU - Feudel, Frank
AU - Biehler, Rolf
ID - 35822
IS - 1
JF - Journal für Mathematik-Didaktik
KW - Education
KW - General Mathematics
SN - 0173-5322
TI - Students’ Understanding of the Derivative Concept in the Context of Mathematics for Economics
VL - 42
ER -
TY - CHAP
AU - Fleischer, Yannik
AU - Biehler, Rolf
ED - Siller, H.-S.
ED - Weigel, W.
ED - Wörler, J. F.
ID - 35823
T2 - Beiträge zum Mathematikunterricht 2020
TI - Automatisierte Entscheidungsverfahren als Thema im allgemeinbildenden Mathematikunterricht
ER -
TY - JOUR
AU - Griese, Birgit
AU - Nieszporek, Ralf
AU - Biehler, Rolf
ID - 35826
IS - 1
JF - Stochastik in der Schule
TI - Frei verfügbare Materialien für Unterricht und Fortbildung: Stochastik verständnisorientiert unterrichten
VL - 40
ER -