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147 results on '"Ivashina, Marianna V."'

5. Performance of Polarimetric Beamformers for Phased Array Radio Telescopes

Author

Ivashina, Marianna V., Wijnholds, Stefan J., Maaskant, Rob, and Warnick, Karl F.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The results of four recently introduced beamforming schemes for phased array systems are discussed, each of which is capable to provide high sensitivity and accurate polarimetric performance of array-based radio telescopes. Ideally, a radio polarimeter should recover the actual polarization state of the celestial source, and thus compensate for unwanted polarization degradation effects which are intrinsic to the instrument. In this paper, we compare the proposed beamforming schemes through an example of a practical phased array system (APERTIF prototype) and demonstrate that the optimal beamformer, the max-SLNR beamformer, the eigenvector beamformer, and the bi-scalar beamformer are sensitivity equivalent but lead to different polarization state solutions, some of which are sub-optimal., Comment: 4 pages, 7 figures, URSI GASS, Turkey, Istanbul, 14-19th Augustus, 2011

Published
2011

15. A mm-Wave Phased-Array Fed Torus Reflector Antenna With ±30° Scan Range for Massive-MIMO Base-Station Applications

Author

Elsakka, Amr, primary, Farsaei, Amirashkan, additional, van den Biggelaar, A. J., additional, Reniers, Adrianus Cornelis Franciscus, additional, Johansson, Martin N., additional, Maaskant, Rob, additional, Johannsen, Ulf, additional, Iupikov, Oleg A., additional, Smolders, A. Bart, additional, and Ivashina, Marianna V., additional

Published
2022
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22. Decoupling efficiency of a wideband Vivaldi focal plane array feeding a reflector antenna

Author

Ivashina, Marianna V., Kehn, Malcolm Ng Mou, Kildal, Per-Simon, and Maaskant, Rob

Subjects
Radiation -- Analysis, Antennas (Electronics) -- Analysis, Business, Computers, Electronics, Electronics and electrical industries
Abstract

A focal plane array (FPA) feeding a reflector can be used to achieve a large field of view (FOV) with overlapping simultaneous beams. In order to provide a continuous FOV over more than an octave bandwidth, the inter-element spacing in the FPA has to be electrically small over large parts of the band. This will inevitably result in strong mutual coupling effects between the array elements. On transmit, the total lost power due to mutual coupling can be quantified by the decoupling efficiency, a term recently introduced for antenna arrays. This paper presents measured decoupling efficiencies of a Vivaldi element FPA operating between 2.3 and 7 GHz. The radiation patterns of the FPA are calculated for two beam excitations by using measured embedded dement patterns, and the corresponding decoupling efficiencies are evaluated by using measured S-parameters between all element ports. The FPA is assumed to illuminate a deep reflector with F/D = 0.35, and the overall reflector aperture efficiencies are computed. The decoupling efficiencies are also determined through the measurements of the total radiation efficiencies in a reverberation chamber, which includes material absorption losses. Index Terms--Antenna array feed, aperture efficiency, decoupling efficiency, mutual coupling, radiation efficiency, tapered slot antenna array.

Published
2009

29. Multi-panel sparse base station design with physical antenna effects in massive MU-MIMO

Author

Amani, Navid, Wymeersch, Henk, Johannsen, Ulf, Smolders, Adrianus Bart, Ivashina, Marianna V., Maaskant, Rob, Electromagnetics, Signal Processing Systems, Center for Wireless Technology Eindhoven, Center for Astronomical Instrumentation, EIRES Eng. for Sustainable Energy Systems, EAISI High Tech Systems, EM Antenna Systems Lab, and EM for Radio Science Lab

Subjects
Beamforming, Computer Networks and Communications, Computer science, MIMO, mutual coupling, Aerospace Engineering, zero-forcing, 02 engineering and technology, Electrical Engineering, Electronic Engineering, Information Engineering, Effective radiated power, Interference (wave propagation), Precoding, beamforming, Sparse array, 0203 mechanical engineering, Telecommunications link, Electronic engineering, massive MIMO, Electrical and Electronic Engineering, Computer Science::Information Theory, 020302 automobile design & engineering, Base station antenna, Multi-user MIMO, Automotive Engineering, Antenna (radio), Antenna gain, sparse array, Multipath propagation, Communication channel
Abstract

A novel base station antenna (BSA) configuration is presented to mitigate degrading physical antenna effects in massive multiple-input multiple-output (MIMO) systems, while minimizing implementation complexities. Instead of using a commonly considered single antenna panel comprising of many elements covering a wide field-of-view (FOV) of 120 degrees, $L$ tilted panels are used employing $L$ times fewer elements and $L$ times smaller FOV per panel. The spatial resolution of each panel is enhanced by employing sparse arrays with suppressed (grating-lobe) radiation outside its corresponding FOV. Therefore, more directive antenna elements can be deployed in each panel to compensate for the effective isotropic radiated power (EIRP) reduction. While sectorisation reduces the antenna gain variation in 120 degrees FOV, cooperation among multiple panels in downlink beamforming is seen to be capable of inter-panel interference suppression for sum-rate enhancement. A network model is used as a multi-user (MU) MIMO simulator incorporating both antenna and channel effects. It is shown that when the number of base station antennas is ten times the number of users, the average downlink sum-rate in pure line-of-sight (LOS), rich and poor multipath environments is increased up to 60.2%, 23% and 11.1%, respectively, by multi-panel sparse arrays applying zero-forcing (ZF) precoding.

Published
2020

34. Wide Scan-Range PAF Telescope for Massive-MIMO 5G Base-Stations

Author

Amr Elsakka, Ulf Johannsen, Iupikov, Oleg A., Johansson, Martin N., Ivashina, Marianna V., Adrianus Bernardus Smolders, Electromagnetics, Center for Astronomical Instrumentation, Center for Wireless Technology Eindhoven, Electrical Engineering, EM Antenna Systems Lab, and EM for Radio Science Lab

Abstract

With the emergence of the mobile fifth generation (5G), additional challenges are introduced for the radio access antennas at the base stations that operate at mm-waves. The base station antenna is then required to deliver high EIRP to compensate for the high path loss at mm-wave frequencies. Furthermore, the massive-MIMO concept is aimed to be applied to increase the overall system capacity. For these reasons, assuming traditional phased arrays, the number of antenna elements is expected to be large which will lead to high power consumption and the need for active cooling. In this presentation, the PAF reflector antenna concept will be proposed aiming at utilizing the reflector’s high gain to produce high EIRP. That can be achieved by utilizing a small number of active elements in the focal plane thanks to the reflector antenna’s focusing properties. Moreover, multibeam generation and steering is provided by exciting different antenna elements in the reflectors focal plane. This way, high EIRP can be generated while reducing the power consumption. At the symposium, a designed PAF reflector will be presented along with relevant simulation results of the past and ongoing research.

Published
2019

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