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European Conference on Microwave

作者： Benedikt Sievert Jonathan Bott Nils Pohl Daniel Erni Andreas Rennings Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR Germany Institute of Integrated Systems Ruhr University Bochum Germany General and Theoretical Electrical Engineering (ATE) University of Duisburg-Essen Germany CENIDE – Center for Nanointegration Duisburg-Essen Germany

ISBN: (数字)9782874870774

ISBN: (纸本)9798350385892

This paper presents a straightforward solution to increase the bandwidth of a rectangular on-chip microstrip patch antenna by exciting the fundamental resonance along the long and short edges of the patch. By a suitable combination of both resonances using quarter-wave transformers, the patch will radiate either a vertical or horizontal polarization in dependence on the frequency, ultimately increasing the usable antenna bandwidth. Here, an overall increased antenna mismatch is tolerated to achieve a relatively flat realized gain over a large bandwidth. The prototype fabricated in Infineon’s B11HFC SiGe BiCMOS process is characterized in a far-field measurement setup and shows the desired increased bandwidth. Furthermore, the disturbing radiation of on-wafer probes on such far-field measurements is shown. For this purpose, a raster scan of the radiated near-field close to the chip is carried out and evaluated.

关键词： Antenna measurements Microwave measurement Semiconductor device measurement Patch antennas Bandwidth Radar Radar antennas System-on-chip Frequency measurement Probes

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Dynamically reconfigurable multi-wavelength interferometry

arXiv

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arXiv 2025年

作者： Voßgrag, Leonard Breunig, Ingo Schiller, Annelie Seyler, Tobias Fratz, Markus Bertz, Alexander Carl, Daniel Laboratory for Optical Systems Department of Microsystems Engineering - IMTEK University of Freiburg Georges-Koehler-Allee 102 Freiburg79110 Germany Fraunhofer Institute for Physical Measurement Techniques IPM Georges-Koehler-Allee 301 Freiburg79110 Germany

Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough, industrially relevant ones due to limited unambiguous measuring range and speckle effects. Multi-wavelength interferometry addresses these challenges by using synthetic wavelengths, enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths. This approach holds immense potential for diverse industrial applications, yet it remains largely untapped due to the lack of suitable light sources. Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds. We demonstrate a light source for multi-wavelength interferometry based on electro-optic single-sideband modulation. It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching times below 30 ms. This breakthrough paves the way for dynamic, reconfigurable multi-wavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings. These capabilities unlock the full potential of multi-wavelength interferometry, offering unprecedented flexibility and speed for industrial and technological applications. © 2025, CC BY-NC-ND.

关键词： Interferometry

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Quantifying the rear side contribution in bifacial tandem-photovoltaic devices

EES Solar

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EES Solar 2024年第1期1卷 66-77页

作者： D. Chojniak M. Steiner S. K. Reichmuth A. Schmid G. Siefer S. Hooper D. Bushnell D. Kirk C. Case S. W. Glunz Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstr. 2 79110 Freiburg Germany Chair for Photovoltaic Energy Conversion Department of Sustainable Systems Engineering (INATECH) University of Freiburg Emmy-Noether-Str. 2 79110 Freiburg Germany Oxford PV Unit 7-8 Oxford Pioneer Park Mead Rd Oxford UK

Bifaciality is a common approach to increase the power output of photovoltaic devices by capturing a higher portion of the available irradiance. The combination of bifacial and tandem architecture gained significant attention in recent years. However, their accurate characterization remains challenging, hindering device comparisons and the assessment of different development approaches. The procedures for single-junction bifacial devices outlined in IEC TS 60904-1-2 are not fully applicable to two-terminal tandem devices due to current limiting effects. In this study, a combination of simulated and measured data is used to propose new parameters to describe the spectral characteristics of bifacial tandem devices. Those parameters are the short-circuit current and maximum power gain factors σ_{I_SC} and σ_{P_MPP} as well as the rear side irradiance limit (RIL). Based on these parameters a bifacial perovskite on silicon single-cell module is characterized performing outdoor measurements. Comparing measurements with an open and a covered rear side, a novel approach to quantitatively determine the bifaciality characteristics of bifacial tandem devices is introduced. For the first time, this enables scaling of measured I_SC and P_MPP values to different rear irradiances. This represents an important step towards a standardized measurement procedure for such devices. Finally, optimization approaches for bifacial tandem devices are proposed based on the presented results.

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Low-Power Modular Multi-Sensor Node with ZeSCIP Analog Frontend 13

Low-Power Modular Multi-Sensor Node with ZeSCIP Analog Front...

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2020 IEEE Congress on Cybermatics: 13th IEEE International Conferences on Internet of Things, iThings 2020, 16th IEEE International Conference on Green Computing and Communications, GreenCom 2020, 13th IEEE International Conference on Cyber, Physical and Social Computing, CPSCom 2020 and 6th IEEE International Conference on Smart Data, SmartData 2020

作者： Jotschke, Marcel Prabakaran, Harsha Reich, Torsten Fraunhofer IIS/EAS Fraunhofer Institute for Integrated Circuits Division Engineering of Adaptive Systems Dresden Germany

ISBN: (纸本)9781728176475

The Zero-Power Signal Conditioning IP (ZeSCIP) aims to operate in an autonomous environmental sensor node with energy harvester-extended life time. In this application, the sensor analog frontend has to process environmental signals of different nature, while it is confronted with power and space limitations and low operating voltages. In a flexible modular setup, the ZeSCIP analog frontend is attached to commercial sensors, which represent a specific air quality sensing scenario. This multi-sensor module is stacked to an ARM Cortex M4-based STM32 Nucleo™ board, creating an operational test setup of a modular sensor node, controlled via USB link. In measurement, the module consumes only 35.5\ μ W during processing of light, CO gas and temperature sensor signals, which makes it suitable to be autonomously powered by energy harvesters. © 2020 IEEE.

关键词： Sensor nodes

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Integrated Satellite Access to 5G/6G systems - An Overview of the 5G Space Infrastructure Study 39

Integrated Satellite Access to 5G/6G Systems - An Overview o...

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39th International Communications Satellite systems Conference, ICSSC 2022

作者： Zaglauer, Helmut W. Pfeifle, Joerg Gavras, Anastasius Kapovits, Adam Corici, Marius Chowdhury, Ananya Frank, Leo Hofmann, Alexander Heyn, Thomas Dang, Thi Uyen Ly Cheporniuk, Hlib Völk, Florian Schwarz, Robert Knopp, Andreas Guta, Maria Airbus Defence and Space GmbH Space Systems Engineering Immenstaad Germany EURESCOM GmbH Heidelberg Germany Fraunhofer FOKUS Institute Berlin Germany Erlangen Germany Bundeswehr University Munich Germany European Space Agency Telecommunications and Integrated Applications Directorate Noordwijk Netherlands

ISBN: (纸本)9781839538841

With Release 17 3GPP has provided the first specification for the integration of satellite networks in the 5G Mobile Telecommunications System. This represents a huge opportunity for the space industry to address new markets and serve many additional use cases through seamless integration into the global mainstream telecommunications ecosystem. To fully realize this potential the satellite community has to deliver suitable concepts and visions and above all a credible roadmap for their timely implementation. For this purpose a study was initiated by the European Space Agency focused on the development of a globally competitive space-based infrastructure - consisting of a space, ground, user and network segment and operational concept - as complement to terrestrial networks providing 5G, beyond 5G and 6G connectivity. To achieve this, user requirements and needs of relevant vertical markets were translated into mission and system requirements as basis for end-to-end architecture options. In order to enable the timely implementation of the proposed concepts, the study provided a comprehensive roadmap for the maturation of critical technology elements and suggested suitable deployment and procurement models for the necessary space and ground segments elements of future 5G NTN system components with a time horizon of 5 and 10 years. © 2022 Proceedings of the Design Society. All rights reserved.

关键词： Commerce

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Pump tuning of a microresonator mid-infrared χ(2) OPO and microcomb generation at 3.1 µm with CdSiP2

Pump tuning of a microresonator mid-infrared χ(2) OPO and m...

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2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023

作者： Amiune, Nicolas Zawilski, Kevin Schunemann, Peter Kordts, Arne Holzwarth, Ronald Buse, Karsten Breunig, Ingo Laboratory for Optical Systems Department of Microsystems Engineering - IMTEK University of Freiburg Georges-Köhler-Allee 102 FreiburgD-79110 Germany BAE Systems Inc. MER15-1813 P.O. Box 868 NashuaNH03061-0868 United States Menlo Systems GmbH Bunsenstraße 5 MartinsriedD-82152 Germany Fraunhofer Institute for Physical Measurement Techniques IPM Georges-Köhler-Allee 301 FreiburgD-79110 Germany

ISBN: (纸本)9798350345995

Over the past decade, there has been a lot of progress in the development of compact single-frequency light sources and frequency combs based on microresonators and nonlinear optics. However, the mid-infrared (MIR) wavelength range still remains challenging to access with these devices while keeping a small footprint [1]. Some approaches rely on bulk MIR laser sources to pump microcombs, while others rely on converting near-infrared frequency comb sources to the MIR. In a different manner, quantum cascade lasers are a promising candidate as compact sources in the MIR but are limited to specific wavelengths and require high electrical powers. © 2023 IEEE.

关键词： Microresonators

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Production planning and process optimization of a cell finishing process in battery cell manufacturing

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Procedia CIRP 2022年 112卷 507-512页

作者： Johannes Wanner Max Weeber Kai Peter Birke Alexander Sauer Fraunhofer Institute for Manufacturing Engineering and Automation IPA Nobelstrasse 12 70569 Stuttgart Germany Electrical Energy Storage Systems Institute for Photovoltaics University of Stuttgart Pfaffenwaldring 47 70569 Stuttgart Germany

In the layout of battery cell manufacturing, the formation process is a cost and area intensive process step. Different process parameters significantly influence the machine utilization, the energy flow, and the output of the cell manufacturing. This usually leads to non-optimally sized and operated formation lines. Therefore, a basic and optimal layout, as well as an optimized production flow, is presented here. The process optimizations of the cell finishing process are carried out using discrete event simulation. In addition to the process parameters, the process costs, the process energy, as well as regulatory framework conditions are also considered. This approach promotes transparency and reliability in the planning and operation of future formation processes in battery cell manufacturing.

关键词： battery cell manufacturing formation process layout process optimization

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Influence of co-reactants on surface passivation by nanoscale hafnium oxide layers grown by atomic layer deposition on silicon †

RSC Applied Interfaces

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RSC Applied Interfaces 2024年第3期1卷 471-482页

作者： Sophie L. Pain Edris Khorani Anup Yadav Tim Niewelt Antonio Leimenstoll Brendan F. M. Healy Marc Walker David Walker Nicholas E. Grant John D. Murphy School of Engineering University of Warwick Coventry CV4 7AL UK sophie.l.pain@warwick.ac.uk Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstraße 2 79110 Freiburg Germany Chair for Photovoltaic Energy Conversion Institute for Sustainable Systems Engineering University of Freiburg Emmy-Noether-Straße 2 79110 Freiburg Germany Department of Physics University of Warwick Coventry CV4 7AL UK

Hafnium oxide thin films have attracted considerable interest for passivation layers, protective barriers, and anti-reflection coatings. Atomic layer deposition offers a route to produce conformal films at the nanometre scale, but there is a lack of clarity over how the growth conditions affect the film properties. Here we present a study into the role of different atomic layer deposition co-reactants (O 2 plasma, O 3 and H 2 O) in the growth of HfO x on n-type silicon from a tetrakis(dimethylamido)hafnium (TDMAH) precursor followed by post-deposition annealing (up to 500 °C). Through X-ray diffraction and X-ray photoelectron spectroscopy, we demonstrate variations in film composition, stoichiometry and crystallinity with co-reactant. Depth profiling conducted with X-ray photoelectron spectroscopy reveals differences in composition between the HfO x surface and the HfO x /Si interface. We also determine differences in fixed charge density and chemical passivation through photoconductance decay measurements and Kelvin probe analysis. We find surface recombination velocities (SRVs) <10 cm s −1 are possible for HfO x films, with the best passivation achieved for H 2 O-based HfO x (SRVs as low as ∼5 cm s −1 ). With TDMAH as a hafnium precursor, we show that neither co-reactant choice nor annealing environment influence the resulting charge polarity.

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Monolithically Integrated 940 nm VCSELs on Bulk Ge Substrates

Monolithically Integrated 940 nm VCSELs on Bulk Ge Substrate...

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IEEE International Conference on Group IV Photonics

作者： Zeyu Wan Yun-Cheng Yang Wei-Hsin Chen Chih-Chuan Chiu Yunlong Zhao Markus Feifel Lukas Chrostowski David Lackner Chao-Hsin Wu Guangrui Xia Department of Materials Engineering The University of British Columbia Vancouver Canada Graduate Institute of Electronics Engineering National Taiwan University Taipei Taiwan Graduate Institute of Photonics and Optoelectronics National Taiwan University Taipei Taiwan Graduate School of Advanced Technology National Taiwan University Taipei Taiwan Fraunhofer Institute for Solar Energy Systems Heidenhofstrasse Freiburg Germany Department of Electrical and Computer Engineering The University of British Columbia Vancouver Canada

ISBN: (数字)9798350394047

ISBN: (纸本)9798350394054

This work successfully developed an independent Ge-VCSEL epitaxy and fabrication technology route. This is the second successful Ge-VCSEL technology reported worldwide, and the first Ge-VCSEL technology with key details disclosed, including Ge substrate specification, transition layer structure and composition, and fabrication process etc. Compared with the GaAs counterparts, after epitaxy optimization, the Ge-VCSEL wafer has a 40% lower surface root-mean square roughness and 72% lower average bow-warp. Additionally, the Ge-VCSEL has a 10% lower threshold current density and a 19% higher maximum slope efficiency than the GaAs-VCSEL.

关键词： Gallium arsenide Surface morphology Germanium Threshold current Surface roughness Epitaxial growth Rough surfaces

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Improved Contact Stability for Admittance Control of Industrial Robots with Inverse Model Compensation

Improved Contact Stability for Admittance Control of Industr...

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IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Kangwagye Samuel Kevin Haninger Sami Haddadin Sehoon Oh Chair of Robotics and Systems Intelligence Munich Institute of Robotics and Machine Intelligence (MIRMI) Technical University Munich Munich Germany Department of Mechanical and Production Engineering Kyambogo University Kampala Uganda Department of Automation Fraunhofer IPK Berlin Germany Department of Robotics and Mechatronics Engineering DGIST Daegu Korea

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

Industrial robots have increased payload, repeatability, and reach compared to collaborative robots, however, they have a fixed position controller and low intrinsic admittance. This makes realizing safe contact challenging due to large contact force overshoots in contact transitions and contact instability when the environment and robot dynamics are coupled. To improve safe contact on industrial robots, we propose an admittance controller with inverse model compensation, designed and implemented outside the position controller. By including both the inner loop and outer loop dynamics in its design, the proposed method achieves expanded admittance in terms of increasing both gain and cutoff frequency of the desired admittance. Results from theoretical analyses and experiments on a commercial industrial robot show that the proposed method improves rendering of the desired admittance while maintaining contact stability. We further validate this by conducting actual assembly tasks of plug insertion with fine positioning, switch insertion onto the rail, and colliding the robot end effector with random objects and surfaces, as seen at https://***/8XfkdHEdWDs.

关键词： Service robots Contacts Dynamics Cutoff frequency Observers Industrial robots Stability analysis Admittance Thermal stability Payloads

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