https://ars.copernicus.org/articles/ Recent articles of the journal Advances in Radio Science https://doi.org/10.5194/ars-23-127-2026 <b>Comprehensive signal processing approaches for non-contact heartbeat detection using 24 GHz FMCW radar</b><br> Aly Marnach, Volker Lücken, and Andreas R. Diewald<br> Adv. Radio Sci., 23, 127–138, https://doi.org/10.5194/ars-23-127-2026, 2026<br> Monitoring vital signs without direct contact improves patient comfort and reduces measurement disturbances. Our research explores a radar-based approach to detect heartbeats without sensors attached to the body. Using a 24 GHz radar system, we developed advanced signal processing methods to ensure accurate detection. The results closely match conventional ECG (electrocardiography) measurements, demonstrating the potential of radar technology for future medical and home-care applications. 2026-02-17T18:03:52+01:00 https://doi.org/10.5194/ars-22-87-2026 <b>A review of orthogonal waveforms for spaceborne Multiple-Input Multiple-Output Synthetic Aperture Radar</b><br> Tobias Rommel, Marwan Younis, and Madhukar Chandra<br> Adv. Radio Sci., 22, 87–103, https://doi.org/10.5194/ars-22-87-2026, 2026<br> Our paper reviews orthogonal waveforms for spaceborne Multiple-Input Multiple-Output Synthetic Aperture Radar (MIMO-SAR), a first-of-its-kind comparison. We provide a catalogue of waveform performance parameters and an ambiguity function analysis, serving as decision rules for optimal waveform selection in MIMO-SAR design. 2026-01-09T18:03:52+01:00 https://doi.org/10.5194/ars-23-113-2026 <b>Concepts for a cost-efficient, additively manufactured WR90 coaxial waveguide transition</b><br> Marius Falk, Simon Müller, Volker Lücken, and Andreas R. Diewald<br> Adv. Radio Sci., 23, 113–126, https://doi.org/10.5194/ars-23-113-2026, 2026<br> This study explores low-cost manufacturing of waveguide components for radio frequency applications. Using 3D printing and metallic coatings, performance is optimized while reducing costs. Tests show improved conductivity enhances efficiency. The findings highlight additive manufacturing as a viable alternative to industrial components, making high-frequency technology more accessible. 2026-01-06T18:03:52+01:00 https://doi.org/10.5194/ars-23-101-2025 <b>A hybrid algorithm to process millimeter wave images with prism-shaped aperture</b><br> Marvin Holder, Mark Eberspächer, and Christian Waldschmidt<br> Adv. Radio Sci., 23, 101–111, https://doi.org/10.5194/ars-23-101-2025, 2025<br> Radar waves are able to penetrate through materials like cardboard or plastics and thus are able to inspect hidden objects. A 3D inspection system based on radar imaging is introduced. Opposed to X-Ray imaging, no harmful radiation is used. The system scans through the object, while it is passing on a conveyor belt. The inspection system uses a curved antenna layout, which is shown to have higher resolution than flat layouts. For processing, a custom flexible and performant algorithm is derived. 2025-12-11T18:03:52+01:00 https://doi.org/10.5194/ars-23-87-2025 <b>Frequency-Selective Dual Linearly Polarized 76 to 81 GHz Automotive Radar System Concept for Street Condition Monitoring</b><br> Sadam Hussain Kazimi, Waqar Ali Shah, Sascha Reuner, Dennis Vollbracht, and Madhukar Chandra<br> Adv. Radio Sci., 23, 87–99, https://doi.org/10.5194/ars-23-87-2025, 2025<br> This paper presents a cost-effective automotive radar system that monitors street conditions while maintaining standard radar operations. Using a novel frequency-selective approach, the system operates at 76.5 GHz for standard radar operations and 80.5 GHz for street condition monitoring, eliminating the need for additional hardware. The findings demonstrate reliable detection of different street types and conditions, enhancing vehicle safety in diverse environments. 2025-10-21T18:03:52+02:00 https://doi.org/10.5194/ars-23-79-2025 <b>Ignition Tests using Electromagnetic Waves in Explosive Atmospheres</b><br> Frauke Kathinka Helene Gellersen, Carola Schierding, Karsten Kuhlmann, and Michael Beyer<br> Adv. Radio Sci., 23, 79–86, https://doi.org/10.5194/ars-23-79-2025, 2025<br> This study explores how electromagnetic waves at 92 GHz potentially ignite explosive atmospheres. Different materials were exposed to high-frequency waves and the resulting temperature increase was measured. A material was selected and controlled ignition tests in explosive gas-air mixtures were conducted. The results show that up to 800 mW can be safely used without triggering an explosion. This suggests that current safety standards (limited to 60 GHz) could be expanded to higher frequencies. 2025-09-12T18:03:52+02:00 https://doi.org/10.5194/ars-23-71-2025 <b>Application of two movable antennas in a compact radar test range for angular measurements</b><br> Markus Tafertshofer, Oliver Arnold, Kilian Hampp, and Erwin Biebl<br> Adv. Radio Sci., 23, 71–78, https://doi.org/10.5194/ars-23-71-2025, 2025<br> This work presents a possible application for radar angular resolution testing. To enable actual conditions, the signal from the radar target simulator is reflected on a parabolic mirror. However, more than one radar target simulator is necessary for angular testing so that they have an offset to the mirror's focal point. The occurring effects,  such as mispositioning and target splitting, are analyzed and explained. Overall, the system is suitable to enable angular resolution testing. 2025-09-01T18:03:52+02:00 https://doi.org/10.5194/ars-23-59-2025 <b>Backscattering-Based Radiation Mode Analysis for Angle Estimation of a CRLH Leaky Wave Antenna</b><br> Jeleel Alao Oladapo, Simon B. Adrian, and Mark A. Eberspächer<br> Adv. Radio Sci., 23, 59–69, https://doi.org/10.5194/ars-23-59-2025, 2025<br> This work explores the special type of passive device to tracking an object without needing its own power source. A special tag placed on the object reflects signals from an external scanner. The scanner sends out waves, and the tag bounces them back, helping detect the objects. The work is aiming at warehouse application to track item boxes in the stock by fixing the tag to the box. 2025-08-29T18:03:52+02:00 https://doi.org/10.5194/ars-23-49-2025 <b>Dual-Frequency SIW Slot Array Antenna for Automotive Radar: configurable FoV, Performance Evaluation, and Tolerance Analysis</b><br> Nooshin Feiz, Sadam Hussain Kazimi, Navid Razi, Pedram Ghasemian, Dennis Vollbracht, and Markus Clemens<br> Adv. Radio Sci., 23, 49–57, https://doi.org/10.5194/ars-23-49-2025, 2025<br> Automotive radar systems help vehicles detect objects and improve safety. This research presents a new antenna design that operates at two different frequencies to enhance both detection range and field of view. The design improves radar performance while keeping the system compact and cost-effective. By carefully analyzing the antenna, its reliability is confirmed. This innovation can support advanced driver assistance systems, making future vehicles safer and more efficient. 2025-08-25T18:03:53+02:00 https://doi.org/10.5194/ars-23-33-2025 <b>Metrological Approach for Identifying Abnormalities and the Causes of Harmonics in Electrical Power Grids using Wavelets</b><br> Helge Lorenzen, Sebastian Koj, and Saba Mylvaganam<br> Adv. Radio Sci., 23, 33–47, https://doi.org/10.5194/ars-23-33-2025, 2025<br> This work shows that continuous wavelet transformation (CWT) is very useful for analyzing transient abnormalities in energy grids. Scalograms are used to visualize the results. It is demonstrated that the family of complex wavelets can be used to analyze the transfer of active power in the power system, even during transient events. This can be used to analyze resonant power grid structures and to identify the causes of violations of current and voltage limits at the grid connection point. 2025-08-18T18:03:53+02:00 https://doi.org/10.5194/ars-23-21-2025 <b>Long-term changes and trends of mesosphere/lower thermosphere gravity waves over Collm, Germany</b><br> Christoph Jacobi, Khalil Karami, Ales Kuchar, Manfred Ern, Toralf Renkwitz, Ralph Latteck, and Jorge L. Chau<br> Adv. Radio Sci., 23, 21–31, https://doi.org/10.5194/ars-23-21-2025, 2025<br> Half-hourly mean winds have been obtained using ground-based low-frequency and very high frequency radio observations of the mesopause region at Collm, Germany, since 1984. Long-term changes of wind variances, which are proxies for short-period atmospheric gravity waves, have been analysed. Gravity wave amplitudes increase with time in winter, but mainly decrease in summer. The trends are consistent with mean wind changes according to wave theory.  2025-05-19T18:03:53+02:00 https://doi.org/10.5194/ars-23-13-2025 <b>Frequency-Dependent Variations of the Antenna Reflection Coefficient Due to Different Wetness Conditions on the Antenna Radome</b><br> Jonas Tiede, Christian Chwala, Uwe Siart, and Thomas F. Eibert<br> Adv. Radio Sci., 23, 13–19, https://doi.org/10.5194/ars-23-13-2025, 2025<br> A hand sprayer is used to deposit droplets on the radome of an antenna. Before and during the drying process, measurements of the antenna reflection coefficient are performed repeatedly over time and frequency using a vector network analyzer. Continuous drifts from the wet state back to the initial dry state are demonstrated for individual antennas and frequency ranges. The obtained insights qualify the antenna reflection coefficient to be a promising indicator of momentary radome wetness. 2025-03-26T18:03:53+01:00 https://doi.org/10.5194/ars-23-1-2025 <b>Spherical-Multipole Analysis of the Scalar Diffraction by a Circular Aperture in a Plane Screen</b><br> Ludger Klinkenbusch<br> Adv. Radio Sci., 23, 1–12, https://doi.org/10.5194/ars-23-1-2025, 2025<br> A new analytical solution for the scalar scattering by a circular aperture in an infinite screen is presented. The field is expanded by means of complete spherical-multipole expansions. The unknown expansion coefficients are found from the conditions of continuity, leading to a quadratic system of linear equations.  The numerical evaluation validates and improves numerical results found in the literature. Further numerical results prove the robustness and convergence of the proposed method. 2025-03-14T18:03:53+01:00 https://doi.org/10.5194/ars-22-77-2025 <b>Modeling Ground-Wave Propagation Across Sea Ice for Radio Navigation Applications</b><br> Niklas Hehenkamp, Lars Grundhöfer, Filippo Giacomo Rizzi, and Stefan Gewies<br> Adv. Radio Sci., 22, 77–86, https://doi.org/10.5194/ars-22-77-2025, 2025<br> The paper describes a method to derive the electrical characteristics of the sea surface from Earth observation data and compute the ground-wave signal delay across sea-ice covered areas.It is used in a tool chain to simulate signal propagation in a real-world scenario for the medium-frequency radio navigation R-Mode and assess the impact of sea ice on the signal propagation delays. The results indicate, that the effect of sea ice is significant and needs to be compensated. 2025-03-13T18:03:53+01:00 https://doi.org/10.5194/ars-22-61-2024 <b>From Schematics to Netlists – Electrical Circuit Analysis Using Deep-Learning Methods</b><br> Dennis Hemker, Jad Maalouly, Harald Mathis, Rainer Klos, and Eranyan Ravanan<br> Adv. Radio Sci., 22, 61–75, https://doi.org/10.5194/ars-22-61-2024, 2024<br> In electronic design development, schematics are used to depict electrical circuits and validate them before manufacturing. As such designs are often handed in as images (bitmaps) only, there is no way to easily process and check them in an automated way.With the help of deep-learning methods, components, lines and text can be extracted from these bitmaps.Fusing these detections, the electrical circuit can be reconstructed and serve as an input for further validation routines. 2024-11-29T18:03:53+01:00 https://doi.org/10.5194/ars-22-53-2024 <b>Using Autoencoders to Classify EMC Problems in Electronic System Development</b><br> Jad Maalouly, Dennis Hemker, Christian Hedayat, Marcel Olbrich, Sven Lange, and Harald Mathis<br> Adv. Radio Sci., 22, 53–59, https://doi.org/10.5194/ars-22-53-2024, 2024<br> This paper aims to classify electromagnetic compatibility (EMC) issues using autoencoders, a dimensionality reduction technique, and machine learning models. The process begins by generating EMC measurement data that closely reflects real-world measurements. The samples are then reduced using autoencoders and used as input for the machine-learning models. The results demonstrate that the machine learning techniques were able to accurately classify between the different EMC classes.  2024-11-29T18:03:53+01:00 https://doi.org/10.5194/ars-22-35-2024 <b>Uncertainties of S-Parameter Measurements in Rectangular Waveguides at PTB</b><br> Andreas Tobias Schramm, Frauke Kathinka Helene Gellersen, and Karsten Kuhlmann<br> Adv. Radio Sci., 22, 35–45, https://doi.org/10.5194/ars-22-35-2024, 2024<br> A systematic analysis of measurement uncertainties in rectangular waveguide calibrations is condcuted. Uncertainty budgets for different waveguide bands are examined, individual uncertainty contributions are discussed and the significant impact of connection repeatability is highlighted. Consequently, an investigation into misaligned waveguide interfaces is undertaken, emphasizing the importance of precise alignment, supported by simulation and experimental data. 2024-11-08T18:03:53+01:00 https://doi.org/10.5194/ars-22-47-2024 <b>Influence of LO cable movements on VNA measurements using Frequency Extensions</b><br> Frauke Kathinka Helene Gellersen, David Ulm, Florian Rausche, Andreas Tobias Schramm, and Karsten Kuhlmann<br> Adv. Radio Sci., 22, 47–52, https://doi.org/10.5194/ars-22-47-2024, 2024<br> In this study, the impact of LO signal variations on VNA measurements is investigated. The effect of LO signal changes is studied through theoretical analysis and experiments. It is found that even minor LO signal phase changes after calibration significantly affect the measured phase angles of transmission coefficients. Error correction terms are derived and applied to correct errors in the experimental data. The results shows that corrected measurements remain unaffected by the effect. 2024-11-08T18:03:53+01:00 https://doi.org/10.5194/ars-22-29-2024 <b>Investigating Electromagnetic Interference Induced Risks for Autonomous Driving</b><br> Tim Brandt, Sven Fisahn, Martin Schaarschmidt, Unai Aizpurua, Erik Kampert, and Stefan Dickmann<br> Adv. Radio Sci., 22, 29–34, https://doi.org/10.5194/ars-22-29-2024, 2024<br> The results of immunity tests on components of self-driving automobiles to radiated high power electromagnetic (HPEM) pulses are presented in this work. It is of particular interest to investigate such automobiles’ resilience towards deliberate attacks with electromagnetic interference (EMI). A characterization of the applied pulses are presented. A correlation can be drawn between the pulse repetition rate or the amplitude of the applied pulses and the severity of the effect on the DUTs. 2024-10-29T18:03:53+01:00 https://doi.org/10.5194/ars-22-17-2024 <b>The Long Road to Entertainment Radio Broadcasting in Germany</b><br> Wolfgang Mathis<br> Adv. Radio Sci., 22, 17–28, https://doi.org/10.5194/ars-22-17-2024, 2024<br> This article deals with the relatively late introduction of entertainment radio in Germany compared to other technically advanced countries. Following current broadcasting history, the German Post Office was initially interested in the commercial use of wireless technology after the end of the First World War. Due to the success of entertainment radio in the USA and UK, there were demands from industry and radio amateurs for its opening in Germany as well, which finally happened with a delay. 2024-09-11T18:03:53+02:00