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UAV-based antenna measurements are of particular interest for physically large antennas, where traditional antenna measurement techniques are not applicable. Precise position information is obtained by GNSS, where the receiving GNSS antenna is a critical system component. An additional antenna groundplane may be beneficial or even required, depending on the antenna design. Appropriate groundplane configurations improved the achievable position accuracy in the majority of investigated cases.

Sporadic E (Es) layers are thin regions of accumulated ions in the lower ionosphere. They can be observed by disturbances of GNSS links between low-Earth orbiting satellites and GNSS satellites. Es layers are influenced by neutral atmospheric tides and show the coupling between the neutral atmosphere and the ionosphere. Here we analyse migrating (sun-synchronous) and non-migrating tidal components in Es. The main signatures are migrating Es, but nonmigrating components are found as well.

Connected cars will be equipped with several wireless transmission technologies. The corresponding exposure of the general public will be significantly influenced by these technologies and must be correctly evaluated. A new measurement procedure suitable for the European vehicle communication standard ITS-G5 together with exposure measurements performed in different cars are described. In comparison with WiFi and Bluetooth, ITS-G5 generated the highest exposure inside a car.

The response of antennas with nonlinear loads is investigated. In this contribution we present a method capable to perform simulations on antennas with multiple nonlinear loads that are less time and memory consuming than traditional proceedings. Moreover, these methods also contribute to a better understanding of observed effects. This is shown using an antenna with two nonlinear loads. A deep insight on how nonlinear loads affect the reception behavior of an antenna will be provided.

The paper gives advice to design sequentially rotated antenna arrays with rotation angles optimized for polarization quality. In antenna arrays perfect single radiators are not realizable. Differences between elements impede efficient operation. A smart approach of placing and rotating the elements improves the radiation characteristics. This effect is very efficient, if the single radiators show medium polarization quality, like e.g., mass produced inexpensive devices used in many applications.

We extend our recent findings regarding various antenna mounting positions, analysing a typical rural street traffic scenario. Varying antenna characteristics are evaluated regarding their communication and sensor suitability to address future intelligent transportation systems based on joint radar-communications. The mirror position with a 16x16 patch array is recommended, whereas for the bumper and the roof less focused antennas like a 4x4 patch array are recommended.

In the state-of-the-art of static magnetic localization of capsule endoscopes relatively large magnets compared with the small capsules are used. Therefore, small disc magnets and ring magnets for integration with the built-in components were evaluated. The mean position and orientation errors did not exceed 5 mm and 4° for all applied magnets except the thinnest disc magnets with a length of 1.5 and 3 mm. Therefore, the state-of-the-art was outperformed even for smaller magnets.

We investigated two different arrangements of Halbach arrays for steering magnetic nanoparticles in cancer therapy. The arrays are arranged with permanent magnets where the strong and weak magnetic sides can be changed by rotating the single magnets. For deriving the magnetic force, two different fitting functions were analyzed and compared. Summarized, the magnetic force and, thus, the region where the particles are able to get washed out, can be adjusted using low-cost permanent magnets.

In measurement applications many devices with two ports have different interfaces at their two ports and are commonly referred to as adapters. The interface e.g. can be a coaxial connector, a rectangular waveguide flange, or a coplanar waveguide probe tip. Two suitable methods for the measurement of such adapters are compared. The first one is a VNA measurement method using only one port calibration standards and one port measurements. It will be compared to a two port calibration method.

Can we control the shape of electromagnetic pulse as radiated from a slot antenna in a given direction? This problem has been resolved in the present paper, where a straightforward signal-processing technique is described analytically and successfully validated numerically.

In near-field in situ measurements the antenna under test may not be accessed to use specifically tailored test signals. Instead there is a need to tackle modulated field signals where short-time measurement approaches offer a way to transform such fields using time-harmonic near- to far-field transformations. Short observation times make such approaches especially useful in measurement scenarios where unmanned aerial vehicles are used to move the field probe.

The technology of ridged-waveguide filters provides high midband frequencies as well as the suppression of spurious passbands up until very high frequencies. Due to the concept of these filters, broad bandwidths lead to reduced filter dimensions that are very difficult to fabricate. The interdigital arrangement of resonators guarantees a more reliable fabrication of these filters. The research was done in order to supply filters for the different frequency bands in the 5G communication standard.

We investigate the variation of the electric power density linked to VLF signals emitted by NWC transmitter. The power density measurements were detected by the Electric Field Detector (EFD) instrument onboard CSES satellite above NWC station and its conjugate region (CR). The beam is subject to disturbances and modulations in CR. Above the NWC station, the beam can be considered as a hollow cone with inconsistency dependence of the half-opening angle on the electric power density.

This publication shows a variety of effects (erroneous sensor data, data communication being disrupted, as well as a complete freeze of all processes) was demonstrated regarding the deliberate manipulation of sensor readings using pulse modulated signals with high field strength and that information will lead to a better understanding of the phenomena occurring at the physical layer of the sensors, so that suitable protection measures can be taken against those type of attacks.

We investigated the impact of Wind Turbines and Wind Turbine Interference on operational weather radar unfiltered raw IQ-data and subsequent radar moments, such as Reflectivity, Differential Reflectivity, Differential Phase, Mean Doppler Velocity and Correlation Coefficient, for both events with and without precipitation in this contribution under the scope of the RIWER (Removing the Influence of Wind Park Echoes in Weather Radar Measurements) project.

This paper demonstrates how probe effects deteriorate mTRL-calibrated S-parameter measurements of conductor-backed CPW structures. A thorough study of CB-CPWs through field analysis is presented and for the first time an analytical description to predict the occurrence of ripples and resonance effects taking the probe geometries into account is presented. The analytical description is verified by em simulation and measurement for two different substrate materials, i.e. fused silica and alumina.