Konferenzbeiträge

In this contribution we present the concept of photon momentum enabled SI-traceably made small force generation and measurements below the conventionally accepted limits. The developed instrumentations, the measurement infrastructure and the obtained results demonstrate the advantages of this concept and further are extended to present the means of systematization of the force measurements covering the range below 10 μN to several tens of nN. The prospects to reduce the relative measurement uncertainties of small force and small weight measurements are discussed.

Automotive navigation is key for modern traffic, which necessitates robust satellite navigation receivers. Distributed antenna arrays can be advantageous with their beam-and null-steering capabilities, however, testing them in the field is resource-intensive and non-repeatable. Therefore, evaluating them in virtual electromagnetic environments is reasonable prior to scheduling field-operational tests. Thereby the challenge arises that the angles-of-arrival of satellite signals deviate from those of their corresponding antennas due to the fixed orbital rotation of satellites and mechanical limitations of physical antenna placements. This discrepancy creates an unrealistic satellite constellation, eventually affecting directions-of-arrival estimation of incident signals which is crucial for interferer suppression. A Matlab tool was implemented to locate satellites near desired transmitter positions and numerically alter their orbital parameters to minimize their angular deviation from respective transmitters. Employing the tool, a realistic virtual satellite constellation with less than 1 degree deviation was emulated and experimentally verified for the test facility.

In satellite communications, it is becoming challenging to provide the tracking performance which is required for Non-Geostationary Orbit (NGSO) constellations with the traditional Satellite Communications (SatCom) On The Move (SOTM) terminal structure which employs bulky parabolic antennas. On the other hand, in terrestrial networks, the single omnidirectional communication with User Equipment (UE) does not provide enough throughput to fulfill the need for higher speed connections. As a consequence, manufacturers started to invest in developing new terminals which use phased array antennas to enable beamforming to increase the directivity and null the interference in terrestrial networks and to provide rapid tracking performance as well as seamless handovers in SOTM. However, this generates new challenge as these antennas change beam patterns depending on the beam steering angle. It is not trivial to evaluate the performance of beamforming antennas since the measurement of the high number of beam patterns that the phased array can form in all directions is time consuming. In this paper, we propose a methodology to measure a large number of beam patterns of a phased array antenna in a more time efficient approach compared to traditional antenna measurement methods. The measured patterns can be used to evaluate the antenna performance and capabilities in different conditions and verify the terminal ability to fulfill the requirements specified by the standards.

Current and upcoming communication and sensing technologies require ever larger bandwidths. Channel bonding can be utilized to extend a receiver’s instantaneous bandwidth beyond a single converter’s Nyquist limit. Two potential joint front-end and converter design approaches are theoretically introduced, realized and evaluated in this paper. The Xilinx RFSoC platform with its 5 GSa/s analog to digital converters (ADCs) is used to implement both a hybrid coupler based in-phase/quadrature (I/Q) sampling and a time-interleaved sampling approach along with channel bonding. Both realizations are demonstrated to be able to reconstruct instantaneous bandwidths of 5 GHz with up to 49 dB image rejection ratio (IRR) typically within 4 to 8 dB the front-ends’ theoretical limits.

This paper presents an experimental measurement platform for the research and development of unmanned aerial vehicles (UAVs) localization algorithms using radio emission and reflectivity. We propose a cost-effective, flexible testbed made from commercial off-the-shelf (COTS) devices to allow academic research regarding the upcoming integration of UAV surveillance in existing mobile radio networks in terms of integrated sensing and communication (ISAC). The system enables nanosecond-level synchronization accuracy and centimeter-level positioning accuracy for multiple distributed sensor nodes and a mobile UAV-mounted node. Results from a real-world measurement in a 16 km^2 urban area demonstrate the system’s performance with both emitter localization as well as with the radar setup.