Dual-polarized architecture for channel sounding at 60 GHz with digital/analog phase control based on 0.25[mu]m SiGe BiCMOS and LTCC technology. - In: Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), (2011), S. 1454-1458
Large-scale parameters of wideband MIMO channel in urban multi-cell scenario. - In: Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), (2011), S. 3759-3763
60 GHz ultrawideband hybrid-integrated dual-polarized front-end in LTCC technology. - In: Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), (2011), S. 1449-1453
A compact dual-polarized wideband patch antenna array for the unlicensed 60 GHz band. - In: Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), (2011), S. 1873-1877
Multimode monopulse tracking feed with dual-band potential for land-mobile satellite communications in Ka-band. - In: Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), (2011), S. 1169-1172
Variation of estimated large-scale MIMO channel properties between repeated measurements. - In: IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011, ISBN 978-1-4244-8332-7, (2011), insges. 5 S.
http://dx.doi.org/10.1109/VETECS.2011.5956676
Singly terminated reconstruction filters for current-mode class-S power amplifiers. - In: IEEE MTT-S International Microwave Symposium digest (MTT), 2011, ISBN 978-1-61284-754-2, (2011), insges. 4 S.
http://dx.doi.org/10.1109/MWSYM.2011.5972705
Low-profile antenna for mobile Ka-band satellite communications. - Online-Ressource (PDF-Datei: 6 S., 691,1 KB)Publ. entstand im Rahmen der Veranst.: 32nd ESA Antenna Workshop on Antennas for Space Applications, 5 - 8 October 2010, ESTEC, Noordwijk, The Netherlands
This paper describes the concept of a low-profile user terminal antenna intended for mobile bi-directional Ka-band satellite communications. The concept addresses a hybrid electronic and mechanical tracking method. The antenna consists of several two-dimensional leaky-wave antenna panels. Each panel is excited by a slotted waveguide feed, composed of a linear array of circularly polarised slots. This structure offers a reconfigurable radiation pattern. As a proof-of-principle, a rectangular antenna panel for the downlink at 20 GHz was manufactured and measured. The paper describes the design of the panel in detail and presents the results of numerical simulation and measurement.
http://www.db-thueringen.de/servlets/DocumentServlet?id=18889
Position determination based on electrical capacitance tomography. - In: Compel, ISSN 2054-5606, Bd. 30 (2011), 4, S. 1224-1236
Purpose - The purpose of this paper is to calculate the two-dimensional (2D) centre position of objects with known shapes based on the reconstruction image of a square sensing area estimated with simulated and measured data by using electrical capacitance tomography (ECT). Design/methodology/approach - A 2D electrostatic finite element model is used to calculate the capacitances between electrode pairs. A reconstruction algorithm with low computation time provides suitable images for subsequent image processing techniques. The results based on numerical data are verified by measurements. Findings - It is possible to calculate the centre position of up to four rod (cross-sectional area about 5 per cent of the measuring area) with an accuracy of 3 per cent in both coordinate directions related to the dimensions of the measuring area. Originality/value - The paper presents an efficient method for position determination of several objects with known shape and uniform permittivity distribution by using ECT measurements with low-cost electronic for industrial application.
http://dx.doi.org/10.1108/03321641111133145
Experimental evaluation of the current-phase relation of a Josephson junction. - In: Compel, ISSN 2054-5606, Bd. 30 (2011), 4, S. 1404-1415
Purpose - Josephson junctions act as active elements in superconducting electronics. The behavior of this nonlinear element is characterized by the relation between current and the quantum mechanical phase-difference. For an accurate device modeling, detailed knowledge about this relation is necessary. This paper aims to discuss these issues. Design/methodology/approach - To obtain detailed information, a method for DC measurement of the current-phase relation suitable for all kinds of superconducting circuit elements was accomplished. Findings - The authors developed a linear transformation algorithm to calculate the current-phase relation from the measured data. Research limitations/implications - It turns out that in future designs additional connections and special test structures are required to gain more knowledge about inductance values required for the algorithm. Originality/value - Based on the inverse calculation of that algorithm, the authors found a 7 percent deviation of the current-phase relation of a standard superconductor/insulator/superconductor Josephson junction from the predicted sine-wave behavior. Furthermore, the paper suggests to use this method to evaluate the current-phase relation of new Josephson elements such as a superconductor/ferromagnet/superconductor junction. Therefore, the authors will deposit the new element directly on the chip with the test setup fabricated with standard Nb-technology. Keywords Electronic engineering, Phase (electronic), Modelling
http://dx.doi.org/10.1108/03321641111133280