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Open Journal of Antennas and Propagation
Number of Followers: 7

This is an Open Access Journal

Open Access journal
ISSN (Print) 2329-8421 - ISSN (Online) 2329-8413
Published by Scientific Research Publishing

[243 journals]

Radar system with dedicated planar traveling wave antennas for elderly
people monitoring
- Abstract: Radar system with dedicated planar traveling wave antennas for elderly people monitoring
  Sassan Schäfer, Simon Müller, Daniel Schmiech, and Andreas R. Diewald
  Adv. Radio Sci., 18, 97–110, https://doi.org/10.5194/ars-18-97-2020, 2020
  In this paper two different antenna topologies for improving the heart beat and breathing detection of people in their homes is shown. A radar system including these antennas for imaging with digital beamforming algorithms has been developed and presented. Measurements are executed and given in this paper with a conclusion.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-97-2020 2020
Respiration parameter determination with non-obstructive methods
- Abstract: Respiration parameter determination with non-obstructive methods
  Sven Fisahn, Christian Siebauer, Jan Ringkamp, Kirsten J. Dehning, Stefan Zimmermann, and Jens Langejürgen
  Adv. Radio Sci., 18, 89–95, https://doi.org/10.5194/ars-18-89-2020, 2020
  In artificial ventilation of neonates uncuffed endotracheal tubes are commonly used. The unknown leakage hampers the detection of spontaneous breathing. A new method to measure respiration by using antennae has recently been presented. A respective setup is investigated numerically and experimentally. Both approaches show that the method seems capable of allowing a contactless triggering to synchronize ventilation. The results are compared to derive a better understanding of influencing factors.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-89-2020 2020
Observations of Solar Type III radio bursts by Cassini/RPWS experiment
- Abstract: Observations of Solar Type III radio bursts by Cassini/RPWS experiment
  Mohammed Y. Boudjada, Ahmed Abou el-Fadl, Patrick H. M. Galopeau, Eimad Al-Haddad, and Helmut Lammer
  Adv. Radio Sci., 18, 83–87, https://doi.org/10.5194/ars-18-83-2020, 2020
  We investigate the solar Type III radio bursts recorded at about 10 AU by Cassini spacecraft. More than 300 bursts have been recorded by the RPWS experiment in the time interval from 01 Jan. 2008 to 31 Dec. 2014. We show that the solar Type III occurrence is mainly depending on the solar activity and also exhibits maxima and minima of detection. The source location of such solar bursts is the interplanetary medium because the dominant emission appears at frequency lower than 2.3 MHz.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-83-2020 2020
Experimental Investigation of a Nonlinear Energy Storage Effect due to
High Power Electromagnetic Excitation
- Abstract: Experimental Investigation of a Nonlinear Energy Storage Effect due to High Power Electromagnetic Excitation
  Robert Michels, Martin Schaarschmidt, and Frank Gronwald
  Adv. Radio Sci., 18, 75–82, https://doi.org/10.5194/ars-18-75-2020, 2020
  The susceptibility of interference victims can significantly be influenced by the presence of nonlinear circuit elements. In addition to the well known occurrence of intermodulation-frequencies, other effects can be observed as well. Recently, a nonlinear energy storage effect has been discovered which is due to the presence of nonlinearly loaded loop antennas if excited by an HPEM-excitation. In this contribution, this effect is further studied by experiment. It is seen that the nonlinear energy storage effect can be reproduced by means of a rather simple experimental setup. This allows to straighforwardly study parameter variations in order to attain an improved understanding of the considered effect.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-75-2020 2020
Approximation and analysis of transient responses of a reverberation
chamber by pulsed excitation
- Abstract: Approximation and analysis of transient responses of a reverberation chamber by pulsed excitation
  Konstantin Pasche, Fabian Ossevorth, and Ralf T. Jacobs
  Adv. Radio Sci., 18, 53–73, https://doi.org/10.5194/ars-18-53-2020, 2020
  Reverberation chambers show transient behaviour when excited with a pulsed signal. The field intensities can in this case be significantly higher than in steady state, which implies that a transient field can exceed predefined limits and render test results uncertain. Effects of excessive field intensities of short duration may get covered and not be observable in a statistical analysis of the field characteristics. In order to ensure that the signal reaches steady state, the duration of the pulse used to excite the chamber needs to be longer than the time constant of the chamber. Initial computations have shown that the pulse width should be about twice as long as the time constant of the chamber to ensure that steady state is reached. The signal is sampled in the time domain with a sampling frequency according to the Nyquist theorem. The bandwidth of the input signal is determined using spectral analysis. For a fixed stirrer position, the reverberation chamber, wires, connectors, and antennas can jointly be considered as a linear time-invariant system. In this article, a procedure will be presented to extract characteristic signal properties such as rise-time, transient overshoot and the mean value in steady state from the system response. The signal properties are determined by first computing the envelope of the sampled data using a Hilbert transform. Subsequent noise reduction is achieved applying a Savitzky–Golay filter. The point where steady state is reached is then computed from the slope of the envelope by utilising a cumulative histogram. The spectral analysis is not suitable to examine the transient behaviour and determine the time constants of the system. These constants are computed applying the method of Prony, which is based on the estimation of a number of parameters in a sum of exponential functions. An alternative to the Prony Method is the Time-Domain Vector-Fit method. In contrast to the first mentioned variant, it is now also possible to determine the transfer function of the overall RC system. Differences and advantages of the methods will be discussed.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-53-2020 2020
Scattering and diffraction of a uniform complex-source beam by a slit in a
perfectly conducting plane screen
- Abstract: Scattering and diffraction of a uniform complex-source beam by a slit in a perfectly conducting plane screen
  Ludger Klinkenbusch
  Adv. Radio Sci., 18, 43–52, https://doi.org/10.5194/ars-18-43-2020, 2020
  A new analytical method has been introduced to exactly solve the classical problem of electromagnetic diffraction by a slit. It is faster and easier to implement than the standard solution using Mathieu functions. Moreover, the paper contains a successful comparison of the scattered fields for an incident plane wave with that one obtained for an incident Gaussian beam which is easily modelled by a complex-source beam.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-43-2020 2020
Characteristic Mode Analysis of surface current distributions on metallic
structures exposed to HIRF- and DCI-excitations
- Abstract: Characteristic Mode Analysis of surface current distributions on metallic structures exposed to HIRF- and DCI-excitations
  Jan Ückerseifer and Frank Gronwald
  Adv. Radio Sci., 18, 33–41, https://doi.org/10.5194/ars-18-33-2020, 2020
  This paper treats Characteristic Mode Analyses of three-dimensional test objects in the context of EMC. Based on computed Characteristic Modes and mode-specific physical quantities, series expansions for HIRF- and DCI-induced surface currents are deduced. The contribution of single Characteristic Modes to surface currents at different test frequencies is analyzed. HIRF- and DCI-excitations are compared with regard to their surface current distributions in their resonance region determined by Characteristic Mode Analysis.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-33-2020 2020
Towards 3D Simulation for Disaster Intervention Robot Behaviour Assessment
- Abstract: Towards 3D Simulation for Disaster Intervention Robot Behaviour Assessment
  Matteo Bertolino and Tullio J. Tanzi
  Adv. Radio Sci., 18, 23–32, https://doi.org/10.5194/ars-18-23-2020, 2020
  The paper presents our work to validate the architecture (software and hardware, including sensors) of ArcTurius Rover. ArcTurius is an autonomous system dedicated to the precise location of survivors after a disaster. To be sure that ArcTurius is adapted to a specific mission, we rely on a set of 3D simulations. In this paper, we focus on finding the best parametrization for a LiDAR sensor. We target to find the best trade-off between the quality of the acquired data and energy consumption.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-23-2020 2020
Near-Field Antenna Measurements with Manual Collection of the Measurement
Samples
- Abstract: Near-Field Antenna Measurements with Manual Collection of the Measurement Samples
  Fabian T. Faul, Hans-Jürgen Steiner, and Thomas F. Eibert
  Adv. Radio Sci., 18, 17–22, https://doi.org/10.5194/ars-18-17-2020, 2020
  Near-field measurements are commonly performed in anechoic chambers which limits the flexibility and requires high precision equipment to achieve exact results. We investigate a simple near-field measurement setup that does not use a sophisticated positioning system nor does it operate in a controlled environment. Instead, the probe antenna is moved by an operator person while its position is measured by a laser tracker. Measurement results are shown to illustrate the performance of the system.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-17-2020 2020
Transparent boundary condition for the calculation of eigenmodes in
transversely infinite waveguides
- Abstract: Transparent boundary condition for the calculation of eigenmodes in transversely infinite waveguides
  Mikhail Patrushev, Wolfgang Ackermann, and Thomas Weiland
  Adv. Radio Sci., 18, 7–16, https://doi.org/10.5194/ars-18-7-2020, 2020
  Waveguides play one of the key figures in today's electronics and optics for signal transmission. Corresponding simulations of electromagnetic wave transportation along these waveguides are accomplished by discretization methods such as the Finite Integration Technique (FIT) or the Finite Element Method (FEM). For longitudinally homogeneous and transversely unbounded waveguides these simulations can be approximated by closed boundaries. However, this distorts the original physical model and unnecessarily increases the size of the computational domain size. In this article we present a boundary condition for transversely open waveguides based on the Kirchhoff integral which has been implemented within the framework of FIT. The presented solution is compared with selected conventional methods in terms of computational effort and memory consumption.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-7-2020 2020
Design of a continuously tunable reflectarray element for 5G metrology in
the k-band
- Abstract: Design of a continuously tunable reflectarray element for 5G metrology in the k-band
  Thomas Harz, Thomas Kleine-Ostmann, and Thorsten Schrader
  Adv. Radio Sci., 18, 1–5, https://doi.org/10.5194/ars-18-1-2020, 2020
  We introduce a new tunable reflectarray element for an operation frequency of 26 GHz in the k-band. It is shown that a 340∘ continuous tunning range of the reflected wave can be accomplished by using an aperture-coupled patch antenna with only one single varactor diode. The simplified design and the small needed space make it usable for k-band reflectarrays with many elements. The functionality of the reflectarray element is explained and the crucial parts are analyzed. The approach to get a full phase shift is discussed in detail. A bias-T is developed to provide the control voltage to the varactor diode without interfering with the high frequency path. The high frequency path and the DC-path are decoupled by 39 dB using a bias-T. A commercial off-the-shelf varactor diode is selected and its functionality at 26 GHz is verified. Therefore, a test printed circuit board with through, reflect, line standards is developed to de-embed the varactor diode and to evaluate it with a vector network analyzer. The reflectarray is simulated in a unit cell with plane wave excitation and periodic boundary condition using the simulation software package CST Microwave Studio™.
  PubDate: Thu, 10 Dec 2020 18:15:37 +010
  DOI: 10.5194/ars-18-1-2020 2020
Verification and first test measurement of a microwave-based vital sign
monitor
- Abstract: Verification and first test measurement of a microwave-based vital sign monitor
  Daniel Schmiech, Aly Marnach, and Andreas R. Diewald
  Adv. Radio Sci., 17, 249–256, https://doi.org/10.5194/ars-17-249-2019, 2019
  One of the most important signs of a living body demonstrating its life-sustaining functions is the respiration rate. State of the art for measuring this vital sign is using a monitoring system cable connected to electrodes which are attached to the patients' skin. Especially in the case of newborn infants this method is not always suitable and causing several problems, like skin injuries, high stress levels and random loosening of the sensor. To avoid these a non-contact system is developed.
  PubDate: Mon, 14 Oct 2019 18:15:37 +020
  DOI: 10.5194/ars-17-249-2019 2019
Realization and opto-electronic Characterization of linear Self-Reset
Pixel Cells for a high dynamic CMOS Image Sensor
- Abstract: Realization and opto-electronic Characterization of linear Self-Reset Pixel Cells for a high dynamic CMOS Image Sensor
  Stefan Hirsch, Markus Strobel, Wolfram Klingler, Jan Dirk Schulze Spüntrup, Zili Yu, and Joachim N. Burghartz
  Adv. Radio Sci., 17, 239–247, https://doi.org/10.5194/ars-17-239-2019, 2019
  Applications in the fields of e.g. industrial image processing, image based robotic control systems and autonomous driving require high dynamic range image sensors. Conventional linear CMOS image sensors only have a limited dynamic range. To extend the dynamic range the concept of a linear self-reset pixel is implemented with several pixel variants being realized and characterized on a CMOS chip. A second topic is the design with digital readout of a cluster structure composed of a pixel matrix.
  PubDate: Fri, 20 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-239-2019 2019
D region observations by VHF and HF radars during a rocket campaign at
Andøya dedicated to investigations of PMWE
- Abstract: D region observations by VHF and HF radars during a rocket campaign at Andøya dedicated to investigations of PMWE
  Ralph Latteck, Toralf Renkwitz, and Boris Strelnikov
  Adv. Radio Sci., 17, 225–237, https://doi.org/10.5194/ars-17-225-2019, 2019
  In April 2018 the PMWE1 sounding rocket campaign was conducted at the Andøya Space Center involving coordinated measurements with rockets and ground instruments to measure parameters relevant for testing of the existing theories of PMWE formation. The Middle Atmosphere Alomar Radar System (MAARSY) was operated to detect PMWE with multiple beam directions. The Saura MF radar was operated with a multiple beam experiment to derive horizontal winds and electron density profiles.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-225-2019 2019
Tidal wind shear observed by meteor radar and comparison with sporadic E
occurrence rates based on GPS radio occultation observations
- Abstract: Tidal wind shear observed by meteor radar and comparison with sporadic E occurrence rates based on GPS radio occultation observations
  Christoph Jacobi and Christina Arras
  Adv. Radio Sci., 17, 213–224, https://doi.org/10.5194/ars-17-213-2019, 2019
  We analyze tidal phases and related wind shear in the mesosphere andlower thermosphere as observed by a meteor radar. The wind shear phases are compared with those of sporadic E occurrence rates, which were derived from GPS radio occultation observations. We find good correspondence between radar derived wind shear and sporadic E phases for the semidiurnal, terdiurnal, and quarterdiurnal tidal components, but not for the diurnal tide.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-213-2019 2019
Estimation of ionospheric reflection height using long wave propagation
- Abstract: Estimation of ionospheric reflection height using long wave propagation
  Dieter Keuer
  Adv. Radio Sci., 17, 205–212, https://doi.org/10.5194/ars-17-205-2019, 2019
  Phase height measurements of low frequency radio waves are used to study the long-term variability of the mesosphere over Europe. But a refinement of this measurements suggest that it must be considered as one that only reflects integral properties of the hole region from the mesosphere over the stratosphere down to the troposphere. The sole coupling of these measurements to the mesosphere must be dropped.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-205-2019 2019
Dielectric corner reflectors for mmWave applications
- Abstract: Dielectric corner reflectors for mmWave applications
  Christian Buchberger, Florian Pfeiffer, and Erwin Biebl
  Adv. Radio Sci., 17, 197–203, https://doi.org/10.5194/ars-17-197-2019, 2019
  This article investigates the properties of dielectric corner reflectors for use in a number of millimeter wave applications, such as road safety for autonomous driving. Material characterizations of different typical plastics using transmission measurements are presented, as well as an analysis of their respective radar cross section (RCS) when used as corner reflectors. They exhibit similar behavior as conventional metallic reflectors, while intrinsic dielectric losses reduce the overall RCS.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-197-2019 2019
Extending the vehicular network simulator Artery in order to generate
synthetic data for collective perception
- Abstract: Extending the vehicular network simulator Artery in order to generate synthetic data for collective perception
  Christoph Allig and Gerd Wanielik
  Adv. Radio Sci., 17, 189–196, https://doi.org/10.5194/ars-17-189-2019, 2019
  A fundamental for an automated driving car is the awareness of its surrounding road participants. Current approach to gather this awareness is to sense the environment by on-board sensors. In the future, Vehicle-to-X (V2X) might be able to improve the awareness. We propose to create synthetic data for investigating cooperative perception by a simulation tool. Therefore, Artery and its counterpart SUMO is extended by modelling realistic vehicle dynamics and probabilistic sensor models.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-189-2019 2019
Singularity Expansion Method for thin wires and the Method of Modal
Parameters
- Abstract: Singularity Expansion Method for thin wires and the Method of Modal Parameters
  Sergey V. Tkachenko, Juergen B. Nitsch, Felix Middelstaedt, Ronald Rambousky, Martin Schaarschmidt, and Ralf Vick
  Adv. Radio Sci., 17, 177–187, https://doi.org/10.5194/ars-17-177-2019, 2019
  Using the method of modal parameters, developed earlier, equations for the Singularity Expansion Method (SEM) poles were obtained. Numerical investigation of solutions for the poles of the fist layer have shown good agreement with analytical and numerical results obtained earlier.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-177-2019 2019
Analysis of an Iterative Approach to Determine the Current on the Straight
Infinite Wire Above Ground
- Abstract: Analysis of an Iterative Approach to Determine the Current on the Straight Infinite Wire Above Ground
  Felix Middelstaedt, Sergey V. Tkachenko, and Ralf Vick
  Adv. Radio Sci., 17, 169–176, https://doi.org/10.5194/ars-17-169-2019, 2019
  An iterative approach which was recently applied to approximate the reflection and scattering coefficients of transmission line ports is analyzed. The iterative solution for the current on an infinite wire above ground is compared to the exact solution. The example is chosen since it is one of the few problems where an exact solution exists. The wire is excited by a lumped voltage source or a plane wave. The convergence of the iterative approach is shown. It can be concluded that the zeroth iteration, which is the classical transmission line solution, coincides with the general transverse electromagnetic mode. Furthermore, it is shown that the first iteration is a very good approximation of the radiation and leaky modes, that occur in the close neighborhood around the lumped source.
  PubDate: Thu, 19 Sep 2019 18:15:37 +020
  DOI: 10.5194/ars-17-169-2019 2019