@misc{Hipp, author = {Hipp, Susanne}, title = {Small antennas in huge environments - simulation using hybrid methods}, series = {Workshop des ITG-Fachausschuss HF1: Innovative Beamforming Antennas}, journal = {Workshop des ITG-Fachausschuss HF1: Innovative Beamforming Antennas}, language = {en} } @misc{Hipp, author = {Hipp, Susanne}, title = {Designing steerable antenna arrays using simulation}, series = {GeMIC 2020}, journal = {GeMIC 2020}, abstract = {Antenna arrays are one possibility to design a steerable antenna. Designing an antenna array is a challenging task, where simulation can help to reduce the design complexity. Simulating a complete array can be computational expensive, therefore designing the array is often broken in several task. The first goal is to design and optimize a single antenna element followed by an optimization of this antenna element while considering the vicinity of further equal elements. A unit cell approach is a feasible and easy way to accomplish this task. This approach already considers parameter such as active element pattern and radiation pattern angles. As soon as the unit cell optimization, emulating an infinite array, is finished, the real array with a finite size is simulated, especially considering edge elements and parameters such as excitation patterns or active and passive elements. Due to the high simulation effort at this stage optimization should be kept to a minimum and high performance computing might be required. Finally, a feeding network and different excitations for various beam patterns can be investigated using combined methods to reduce the simulation effort.}, subject = {Antennengruppe}, language = {en} } @inproceedings{RaspSahinbasReisingeretal., author = {Rasp, Franziska and Sahinbas, Burak and Reisinger, Thomas and Hipp, Susanne and Leitgeb, Erich}, title = {From Ray Tracing to Channel Impulse Responses: A Review on the Description of Polarimetric Time-Invariant SISO Channels}, series = {2024 International Conference on Broadband Communications for Next Generation Networks and Multimedia Applications (CoBCom), 09-11 July 2024, Graz, Austria}, booktitle = {2024 International Conference on Broadband Communications for Next Generation Networks and Multimedia Applications (CoBCom), 09-11 July 2024, Graz, Austria}, publisher = {IEEE}, isbn = {979-8-3503-8845-9}, issn = {2834-8265}, doi = {10.1109/CoBCom62281.2024.10631174}, pages = {1 -- 8}, abstract = {One key enabler of autonomous driving is vehicle-to-everything (V2X) communication and positioning using cellular technologies. To design a vehicular localization system, the understanding and modeling of the physical radio channel (RC) is crucial. Polarization is an important yet often overlooked parameter of the RC. The combined polarization of the transmitting and receiving antennas, along with the environment, significantly affects the Channel Impulse Response (CIR) and localization performance. This paper aims to provide a deterministic description of the time-invariant Single-Input Single-Output (SISO) RC with focus on its polarimetric properties. The aim is to link the understanding of physical wave propagation directly to the conventional CIR descriptions used in localization and signal processing. The focus is on SISO RC modeling for arbitrary antennas, including Line-of-Sight (LoS) and multiple reflections. This study intentionally excludes diffraction, diffuse scattering, and bandwidth limitations, yet establishes a foundational frame-work for future multi-antenna systems with full polarimetric capabilities. The paper describes wave propagation using the Jones Calculus to separate polarimetric wave components, and models the polarimetric reception typical of RC modeling methods in positioning. This approach allows for the calculation of received signal at the antenna feed point. The application context of this research is in ranging or positioning within the V2X framework.}, language = {en} } @inproceedings{RaspEberleinPerneretal., author = {Rasp, Franziska and Eberlein, Ernst and Perner, Bastian and Roth-Mandutz, Elke and Hipp, Susanne}, title = {Enhanced 5G Sidelink Ranging Based on Carrier Aggregation}, series = {2023 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nuremberg, Germany, 25-28 September 2023}, booktitle = {2023 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nuremberg, Germany, 25-28 September 2023}, publisher = {IEEE}, isbn = {9798350320114}, doi = {10.1109/IPIN57070.2023.10332548}, pages = {1 -- 6}, abstract = {Radio access network based positioning and ranging technologies become more and more important for autonomous driving. Positioning on the 5G Sidelink (SL) is discussed in Release 18 (2022-2024) of the Third Generation Partnership Project. For accurate timing-based ranging, a high temporal and spatial resolution is fundamental. The bandwidth for 5G SL positioning is limited due to sharing the existing SL resources with communication. Therefore, we send the positioning reference signal on two separate Component Carriers, i.e. we use a fragmented spectrum. We introduce a two step algorithm for estimating the time of arrival using the inflection point method. We proved a fragmented spectrum can achieve the same accuracy as a continuous spectrum.}, language = {en} } @inproceedings{RaspSahinbasReisingeretal., author = {Rasp, Franziska and Sahinbas, Burak and Reisinger, Thomas and Hipp, Susanne and Leitgeb, Erich}, title = {Experimental Validation of a Full Polarimetric Channel Model with Frequency-Dependent Antenna Gain for Polarization Diversity Studies}, series = {2025 19th European Conference on Antennas and Propagation (EuCAP), 30. March-04. April 2025, Stockholm}, booktitle = {2025 19th European Conference on Antennas and Propagation (EuCAP), 30. March-04. April 2025, Stockholm}, publisher = {IEEE}, isbn = {978-88-31299-10-7}, doi = {10.23919/EuCAP63536.2025.10999403}, pages = {5}, abstract = {Autonomous driving, child presence detection, and digital car keys rely on precise localization. Therefore, accurate simulation environments are essential for designing radio systems and optimizing their positioning algorithms. A critical aspect of developing a reliable localization system is modeling the physical radio channel, which includes the transmitting antenna, the propagation medium, and the receiving antenna. However, existing channel models often overlook important physical effects of antennas, such as frequency dependence and polarization, leading to discrepancies between simulations and real-world measurements. To address this, the paper enhances full polarimetric channel models by incorporating the frequency dependence of both antennas and propagation channels. The theoretical model is validated through Vector Network Analyzer channel sounding measurements using reference antennas. This approach provides a foundation for polarization-based post-processing, ultimately improving positioning accuracy.}, language = {en} } @misc{Marterer, type = {Master Thesis}, author = {Marterer, Verena}, title = {A Characterisation of Motives and Barriers to Taking up Academic Study in the Field of Electrical Engineering}, address = {Regensburg}, doi = {10.35096/othr/pub-6255}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-62550}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {159}, abstract = {The problem description comes to the fore when the wide-ranging subject area of electrical engineering is combined and analyzed with different types of schools. It is becoming increasingly rare for elementary school children to come to grips with technology in the sense of recognizing functional interrelationships and understanding modes of action in the context of technical-practical confrontation. The picture at secondary schools is also rather sobering. Here, a strong focus on facts and knowledge and too little emphasis on modeling, application and problem solving lead to insufficient results in the cognitive area. In addition, a massive shortage of engineers and specialists with a technical and scientific orientation has been predicted for years and is being increasingly observed. The motivation of students in traditional lectures is decreasing and in general there is a decline of university students in technical subjects. These problems are not only known throughout Germany, but also internationally. Especially in developing countries, additional problems make technical education more difficult, regardless of the type of school. Therefore, this master thesis is evaluated in South Africa in order to consider as many influencing factors as possible. "Learning is experience. Everything else is simply information." - Methods and concepts developed in the thesis build upon this quote of Albert Einstein. Teaching methods are elaborated and applied for three different age groups and school types, depending on known influencing factors. The aim of this thesis is not to produce further findings in the sense of basic research, but to show ways in which the current situation can be steered in a different direction. It has been shown that technology lessons in elementary/secondary schools inspire interest in technical professions in the field of electrical engineering. Furthermore, the combination of frontal teaching, for a necessary theoretical background, together with student-active, action-oriented teaching shows advantages in terms of learning efficiency and an increase in performance levels for all three age groups. However, it could also be observed that factors such as social background, family influence and gender have partial effects on the promotion and education in the field of electrical engineering.}, language = {en} } @masterthesis{Marterer, type = {Bachelor Thesis}, author = {Marterer, Verena}, title = {Simulation der elektromagnetischen Eigenschaften von gestricktem Stoff}, address = {Regensburg}, doi = {10.35096/othr/pub-5760}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-57605}, school = {Ostbayerische Technische Hochschule Regensburg}, abstract = {Periodische Strukturen besitzen eine Reihe interessanter Eigenschaften, die sie unter anderem f{\"u}r den Einsatz im Bereich der Hochfrequenz- und Mikrowellentechnik attraktiv erscheinen lassen. In der vorliegenden Arbeit steht insbesondere deren Anwendung beim Entwurf gestrickter Stoffe, die auf metallischen F{\"a}den basieren, im Vordergrund. Es wird in diesem Zusammenhang zun{\"a}chst die vollst{\"a}ndige Modellierung der Struktur unter Verwendung von 3D-Elementen in repr{\"a}sentativen Elementarzellen durchgef{\"u}hrt. Innerhalb der Designumgebung von CST Studio Suite kann das analytische Elementarmodell von Leaf und Glaskin f{\"u}r die Einfaden-Maschenware implementiert werden. Abh{\"a}ngig von den variablen Faktoren beim Stricken bewegen sich die Kantenl{\"a}ngen der hier betrachteten Einheitszelle in der Gr{\"o}ßenordnung von 1 cm bis 2 cm. Bei der Analyse der elektromagnetischen Eigenschaften unter Verwendung eines Frequenzbereichsl{\"o}sers k{\"o}nnen somit die Streuparameter f{\"u}r Reflexion und Transmission in einem Frequenzbereich von 13 GHz bis 30 GHz ermittelt werden. Aus den 1D-Simulationsergebnissen werden Frequenzen sichtbar, bei denen Resonanzph{\"a}nomene auftreten. Die polarisationsabh{\"a}ngigen Strukturen weisen Abschirmwirkungen von 30 dB und mehr auf. Da das Resonanzverhalten mit den Oberfl{\"a}chenstr{\"o}men in Verbindung steht, wird die Oberfl{\"a}chenstromverteilung zeitgleich mit dem elektrischen Feld untersucht. Weiterhin wird den Wechselwirkungen zwischen den ver{\"a}nderlichen Strickparametern und den elektromagnetischen Spezifikationen wie Resonanzfrequenz, Bandbreite oder G{\"u}te Aufmerksamkeit geschenkt. Es wird deutlich, dass Optimierungsroutinen die M{\"o}glichkeit nahelegen, frequenzselektive gestrickte Strukturen f{\"u}r diverse Anwendungen maßzuschneidern.}, language = {de} } @article{MartererRadouchovaSoukupetal., author = {Marterer, Verena and Radouchov{\´a}, Michaela and Soukup, Radek and Hipp, Susanne and Blecha, Tom{\´a}š}, title = {Wearable textile antennas: investigation on material variants, fabrication methods, design and application}, series = {Fashion and Textiles}, volume = {11}, journal = {Fashion and Textiles}, publisher = {Springer Open}, doi = {10.1186/s40691-023-00369-1}, abstract = {With the ongoing miniaturization of wireless devices, the importance of wearable textiles in the antenna segment has increased significantly in recent years. Due to the widespread utilization of wireless body sensor networks for healthcare and ubiquitous applications, the design of wearable antennas offers the possibility of comprehensive monitoring, communication, and energy harvesting and storage. This article reviews a number of properties and benefits to realize comprehensive background information and application ideas for the development of lightweight, compact and low-cost wearable patch antennas. Furthermore, problems and challenges that arise are addressed. Since both electromagnetic and mechanical specifications must be fulfilled, textile and flexible antennas require an appropriate trade-off between materials, antenna topologies, and fabrication methods—depending on the intended application and environmental factors. This overview covers each of the above issues, highlighting research to date while correlating antenna topology, feeding techniques, textile materials, and contacting options for the defined application of wearable planar patch antennas.}, language = {en} } @inproceedings{MartererMuhrSoukupetal., author = {Marterer, Verena and Muhr, Franz-Xaver and Soukup, Radek and Hipp, Susanne and Blecha, Tom{\´a}š}, title = {Material Characterization Using Waveguide Measurement Technique for the Development of Textile Antennas}, series = {2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden, 3/30/2025 - 4/4/2025}, booktitle = {2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden, 3/30/2025 - 4/4/2025}, publisher = {IEEE}, isbn = {978-88-31299-10-7}, doi = {10.23919/EuCAP63536.2025.10999278}, pages = {1 -- 5}, abstract = {Significant advances in using conductive textiles have been made over the past two decades, particularly in knitted fabrics. The aim is to deepen understanding of how knitted structures, especially those with hybrid yarns containing fine conductive elements (microwires), interact with electromagnetic fields. To establish simulation models that align with subsequent measurements, it is crucial to determine the dielectric properties, specifically relative permittivity and loss tangent/conductivity. This research investigates whether knitted structures with hybrid yarns exhibit anisotropic permittivity, meaning different dielectric properties along orthogonal axes within the fabric plane. These properties were measured using a waveguide technique' whereby the structures were rotated by 90° to observe changes. The results demonstrate that the knitted structure exhibits metallic-like reflective behavior in one direction, while rotation leads to dielectric material characteristics. This effect is influenced by the number of conductive microwires and the materials used for these wires, such as silver-plated copper or bronze.}, language = {en} } @misc{Schoen, type = {Master Thesis}, author = {Sch{\"o}n, Matthias}, title = {Implementation and Evaluation of the ESPRIT Algorithm for DoA Estimation on an FPGA-based SDR Platform}, address = {Regensburg}, doi = {10.35096/othr/pub-8688}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-86883}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {vi, 104}, abstract = {Environmental sensing using smart antennas and antenna arrays is a broad field with many applications in different areas. This thesis is part of the initial stage of a longer research project at the OTH Regensburg, with the goal of enhancing the antenna-array-based sensing capabilities of base stations. Existing technologies that utilize radio waves, such as radar, often require the generation of special signals to scan the environment. This project aims to utilize the existing mobile communication traffic instead, making the benefits of sensing capabilities available to a wider range of applications. Many of the array processing methods require high computational power and are used in environments with real-time constraints. Therefore, the use of field-programmable gate arrays (FPGAs) for hardware acceleration of these methods will be investigated, evaluating which methods are suitable for implementation on FPGAs. The focus in this thesis lies on the Estimation of Signal Parameters Via Rotational Invariance Techniques (ESPRIT) method for direction of arrival (DoA) estimation, as it is a popular and highly accurate method that does not rely on calibration. The accelerator is implemented for the RFSoC4x2 software-defined radio (SDR), using Vitis High-Level Synthesis (HLS) for implementation of the algorithm itself, Vivado for the hardware configuration, and Python Productivity on Zynq (PYNQ) for drivers and application code. Simulations for evaluation and verification, as well as test data generation, are implemented in Julia, using a custom array signal processing package. A measurement setup is used to collect experimental data for simulation and evaluation of the performance of the implemented ESPRIT. It is shown that the underlying assumption of equal subarrays does not hold for the array used for the measurements. This causes the estimates to be erroneous and can only be addressed by employing other algorithms that allow for the required calibration.}, subject = {Field programmable gate array}, language = {en} }