@misc{Schubert, author = {Schubert, Martin J. W.}, title = {Verfahren zur Simulation von Netzwerken auf einer ereignisgesteuerten Zeitachse mittels verteilter, lokaler Iteration}, language = {de} } @article{Schubert, author = {Schubert, Martin J. W.}, title = {70V-to-5V Differential CMOS Input Interface}, series = {IEE Electronic Letters}, volume = {30}, journal = {IEE Electronic Letters}, number = {4}, doi = {10.1049/el:19940235}, pages = {296 -- 297}, language = {en} } @inproceedings{Schubert, author = {Schubert, Martin J. W.}, title = {Mixed Signal Modeling in VHDL by Distributed Local Iteration}, series = {VHDL Form, Toledo, Spain, April 20-24, 1997}, booktitle = {VHDL Form, Toledo, Spain, April 20-24, 1997}, language = {en} } @article{LeeSchubertOoietal., author = {Lee, Wai-Kong and Schubert, Martin J. W. and Ooi, Boon Yaik and Ho, Stanley Jian-Qin}, title = {Multi-source energy harvesting and storage for floating wireless sensor network nodes with Long Range Communication Capability}, series = {IEEE Transactions on Industry Applications}, volume = {54}, journal = {IEEE Transactions on Industry Applications}, number = {3}, publisher = {IEEE}, doi = {10.1109/TIA.2018.2799}, pages = {2606 -- 2615}, abstract = {Wireless sensor networks are widely used for environmental monitoring in remote areas. They are mainly composed of wireless sensor nodes, usually powered by batteries with limited capacity, but are expected to communicate in long range and operate for extended time periods. To overcome these limitations, many energy harvesting techniques are proposed to power wireless nodes for prolonged operation, whereas multihop techniques are utilized to extend the communication range. In this paper, a novel floating device with multisource energy harvesting technology that can be used as a wireless sensor node is proposed. The long range communication between wireless sensor nodes and a gateway is established through LoRa technology. In addition to conventional solar panels, an energy harvesting technique based on thermoelectric generators exploiting thermal differences created between water surface and materials exposed to sunlight is proposed. Energy generated from photovoltaic and thermoelectric generators is combined to power the wireless sensor node. This floating device consumes 6.6216 Wh per day when used as a wireless sensor node for the collection and transmission of environmental data. The sensor node can operate on a water surface for at least 9.6 days when it is not exposed to sunlight. During a sunny day, the floating device can harvest 8.375 Wh from solar panels and 0.425 Wh from thermoelectric generation. In other words, the floating device harvests sufficient energy to be self-sustaining during sunny days.}, language = {en} } @article{Schubert, author = {Schubert, Martin J. W.}, title = {An Analog Node Model for VHDL Based Simulation of RF Integrated Circuits}, series = {IEEE Transactions on Circuits and Systems I, Regular Papers}, volume = {56}, journal = {IEEE Transactions on Circuits and Systems I, Regular Papers}, number = {12}, doi = {10.1109/TCSI.2009.2027799}, pages = {2717 -- 2727}, abstract = {This paper describes a very-high-speed integrated-circuit hardware description language (VHDL)-based analog-node model, an associated driver component for the mixed-signal event-driven (MixED) simulation technique, and some primitive device models applied to radio-frequency integrated circuits. With the presented MixED method, analog circuits are modeled as a composition of controlled sources. Unlike other VHDL-based analog simulation methods, these MixED sources compute not only a real number representing an output voltage but also an output impedance. This allows the outputs of several MiXED sources to be connected in order to drive the same node signal n . The voltage of this record-type signal is automatically computed at its element n . u by resolution functions in compliance with Kirchhoff's current law. The data structure of the node signal n , its self-defined resolution functions, and an associated driver component are presented and discussed to meet different simulation requirements, such as speed, versatility, current accuracy, and adaptive time stepping. Several examples demonstrate how to behaviorally model mixed-signal components with this method with an emphasis on the simulation of a heterodyne receiver. Simulation speeds are compared to VHDL-AMS tools.}, language = {en} } @inproceedings{SchubertSeignDaietal., author = {Schubert, Martin J. W. and Seign, Stefan and Dai, Q. and Hinterseer, Sebastian and Pielmeier, F. and Pietsch, Alexander and Seebauer, C. and Weiß, Josef and Yu, C. and Zenger, Stefan}, title = {Capacitive Sensor Technology for Soil Moisture Monitoring Networks}, series = {24th IEEE International Conference on Electronics, Circuits and Systems (ICECS), 5-8 Dec. 2017, Batumi, Georgia}, booktitle = {24th IEEE International Conference on Electronics, Circuits and Systems (ICECS), 5-8 Dec. 2017, Batumi, Georgia}, doi = {10.1109/ICECS.2017.8292018}, pages = {190 -- 193}, abstract = {A sensor technology for tracking soil-moisture in agricultural fields is presented. A linear measurement method was developed to satisfy the need for cheap sensors with wide range of capacitance change such as factor 30. A combined wired and wireless network transmits data to a server. Various battery aspects are compared with respect to use in agriculture.}, language = {en} } @inproceedings{Schubert, author = {Schubert, Martin J. W.}, title = {System Contemplations for Precision Irrigation in Agriculture}, series = {AIP Conference Proceedings}, volume = {1828}, booktitle = {AIP Conference Proceedings}, number = {1}, isbn = {9780735414969}, doi = {10.1063/1.4979393}, abstract = {This communication contemplates political, biological and technical aspects for efficient and profitable irrigation in sustainable agriculture. A standard for irrigation components is proposed. The need for many, and three-dimensionally distributed, soil measurement points is explained, thus enabling the control of humidity in selected layers of earth. Combined wireless and wired data transmission is proposed. Energy harvesting and storage together with mechanical sensor construction are discussed.}, language = {en} } @inproceedings{Schubert, author = {Schubert, Martin J. W.}, title = {VHDL Based Simulation of a Delta-Sigma A/D Converter Clocked with a Phase-Locked Loop}, series = {Design, Automation and Test in Europe, DATE'2001 Conference, March 13-16 2001, Munich}, booktitle = {Design, Automation and Test in Europe, DATE'2001 Conference, March 13-16 2001, Munich}, abstract = {The VHDL based mixed-signal event-driven (MixED) simulation method is employed to simulate a comprehensive system containing a number of mixed-signal building blocks: an analog waveform generator, a phase-locked loop and two ∆Σ modulators for A/D conversion.}, language = {en} } @inproceedings{Schubert, author = {Schubert, Martin J. W.}, title = {VHDL Based Simulation of a Sigma-Delta A/D Converter}, series = {EEE/ACM International Workshop on Behavioral Modeling and Simulation (BMAS2000), October 19-20 2000, Orlando, Florida, USA, prodeedings}, booktitle = {EEE/ACM International Workshop on Behavioral Modeling and Simulation (BMAS2000), October 19-20 2000, Orlando, Florida, USA, prodeedings}, doi = {10.1109/BMAS.2000.888367}, abstract = {The VHDL based mixed-signal event-driven (MixED) simulation method is employed to simulate a sigma-delta modulator for A/D conversion. Results are verified by experimental data and comparison to PSpice-AD simulations.}, language = {en} } @inproceedings{LeeSchubertHo, author = {Lee, Wai-Kong and Schubert, Martin J. W. and Ho, Stanley Jian-Qin}, title = {Multi-source energy harvesting and storage for floating wireless-sensor-network nodes}, series = {2016 IEEE Industrial Electronics and Applications Conference (IEACon 2016), 20.-22. Nov. 2016, Kota Kinabalu, Malaysia}, booktitle = {2016 IEEE Industrial Electronics and Applications Conference (IEACon 2016), 20.-22. Nov. 2016, Kota Kinabalu, Malaysia}, isbn = {9781509009268}, language = {en} } @misc{SchubertSeign, author = {Schubert, Martin J. W. and Seign, Stefan}, title = {Arrangement for Measuring Capacitance}, language = {en} } @article{SchubertHoefflingerSchroederetal., author = {Schubert, Martin J. W. and H{\"o}fflinger, Bernd and Schr{\"o}der, D. and Zingg, Ren{\´e} P.}, title = {1D Modeling of SOI MOSFETs Using Distinct Quasi-Fermi Potentials}, series = {Microelectronic Engineering}, volume = {15}, journal = {Microelectronic Engineering}, number = {1-4}, doi = {10.1016/0167-9317(91)90221-X}, pages = {237 -- 240}, abstract = {Distinct electron and hole quasi-Fermi potentials, {\o}f,n and {\o}f,p, are included into a one-dimensional SOI MOSFET model that accounts for finite inversion and depletion layer thicknesses. The inclusion of {\o}f,n, {\o}f,p in the nonlinear analytical model is demonstrated to describe phenomena like kink effect and the multistable-charge-controlled-memory effect (MCCM) in SOI MOSFETs. The calculation of {\o}f,p(t) depends on the device history and generation/recombination rates.}, language = {en} } @inproceedings{SchubertLeeOoi, author = {Schubert, Martin J. W. and Lee, Wai-Kong and Ooi, Boon Yaik}, title = {Quantization and Sampling Effects in Fast Digitally Controlled Switch-Mode DC/DC Buck Converters}, series = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, booktitle = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, publisher = {IEEE}, isbn = {978-1-7281-9253-6}, doi = {10.1109/IEACon51066.2021.9654272}, pages = {56 -- 61}, abstract = {Software-defined control of DC/DC switch mode power converters features unequaled flexibility compared to analog control. For fast switching converters as recently used for low power applications, digital control may cause steady-state oscillations known as limit cycles. This effect based on a quantized duty cycle is compared to other aberrations such as output ripple voltage, which is inherent to any pulse-width modulator. A distinction is made between DC and AC errors. The latter are divided into synchronous and asynchronous output voltage disturbances. Synchronous AC errors are composed of the switching frequency and its harmonics.}, language = {en} }