| 1. |
- Beukman, Theunis S., 1986, et al.
(författare)
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A Quadraxial Feed for Ultra-Wide Bandwidth Quadruple-Ridged Flared Horn Antennas
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 2164-3342. - 9788890701849 ; , s. 3312 - 3316
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Konferensbidrag (refereegranskat)abstract
- A quadraxial feed, excited by two orthogonal differential modes, is proposed for ultra wideband quadruple-ridged flared horn (QRFH) antennas that obviates the need for a balun. It is shown that in this configuration the fundamental TE11 mode is most strongly excited over the entire frequency band, while the higher-order modes are significantly suppressed, as compared to the conventional excitation using the ridge-to-coax balun transition. These properties lead to several advantages for QRFH antenna applications which require frequency-invariant beam characteristics, high port isolation and low cross-polarisation level, such as e.g. reflector antenna feeds for future radio telescopes.
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| 2. |
- Einarsson, Bjarni Thor, 1987, et al.
(författare)
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Measurements of relative Throughput in Reverberation Chamber using Universal Software Radio Peripheral
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 2164-3342. - 9788890701849 ; , s. 1105-1108
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Konferensbidrag (refereegranskat)abstract
- This paper aims to show how Universal Software Radio Peripheral can be used in conjunction with reverberation chamber to measure throughput of wireless communication systems in Rich Isotropic Multipath environment. The results are in agreement with theories based on the threshold receiver model.
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| 3. |
- Gustafson, Carl, et al.
(författare)
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Modeling the cluster decay in mm-wave channels
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014. - 9788890701849 ; , s. 803-807
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Konferensbidrag (refereegranskat)abstract
- © 2014 European Association on Antennas and Propagation.The cluster power is an important parameter for cluster-based wireless channel models. This paper addresses modeling and estimation of the cluster power for wireless channels. A novel way of estimating the cluster decay and cluster fading, where the effects of the noise floor is taken into account, is presented. Due to the noise floor present in the measurement, only a limited number of clusters are available when estimating the cluster decay. It is shown that the estimated cluster decay and cluster fading can be improved if the effects of the noise floor and cluster fading are modeled and taken into account in the estimation step. If the noise floor is not taken into account in the estimation of the cluster decay, the resulting model can overestimate the RMS delay spread. Further, the paper includes estimates of the cluster decay and fading based on measured clusters for an indoor wireless mm-Wave channel in a conference room environment.
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| 4. |
- Gustafsson, M., et al.
(författare)
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OTA Characterization of mu BTS Antenna in RIMP and Random-LOS
- 2014
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Ingår i: 2014 8th European Conference on Antennas and Propagation (Eucap). Hague, NETHERLANDS. APR 06-11, 2014. - 2164-3342. - 9788890701849 ; , s. 1394-1397
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Konferensbidrag (refereegranskat)abstract
- During the past recent years, Huawei Technologies have had the ambition to strengthen the competence of the company by establishing cooperation projects with strong scientific academic centers in the world. The antenna department at Chalmers University of Technology is identified as one such important knowledge center, and a one year cooperation project was hence defined in 2012 and the project took off by October in the autumn that year. The goal of the project was to identify a compact antenna solution usable for small cell BTS solutions, which would support MIMO up to four layer spatial multiplexing. This paper is a brief summary of the methodology used for the theoretical studies done within the project, as well as a short presentation of the chosen bowtie antenna solution.
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| 5. |
- Jamaly, Nima, 1979, et al.
(författare)
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Analysis and Measurement of Multiple Antenna Systems for Fading Channel Prediction in Moving Relays
- 2014
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Ingår i: 2014 8TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP). - 2164-3342. - 9788890701849 ; , s. 2015-2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The performance of wireless data transmission to mobile vehicles is improved if channel state information is available at the transmitter but movement of vehicles causes outdating of channel estimates. The concept of a predictor antenna has recently been proposed, where an antenna is placed in front of other antennas on the roof of the vehicle to sense the radio environment in advance. This can comparatively provide an order-of-magnitude improvement in channel prediction performance. A potential problem with this idea is that closely placed antennas will experience mutual electromagnetic couplings. These may reduce the efficiency of the predictor antenna concept if they are not taken into account. In this paper, we discuss about how to treat the forgoing issue and eventually evaluate a promising candidate on measured channels. We argue that only open-circuit voltage method would be realistic for the present application. The usefulness of the proposed decoupling method is demonstrated on field measurements obtained in downtown Dresden, Germany. We also partly address the sensitivity of the open-circuit decoupling method to the accuracy of the utilized network parameters.
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| 6. |
- Jian, Qiuchi, 1984, et al.
(författare)
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Detection of breathing and heartbeat by using a simple UWB radar system
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014. - 2164-3342. - 9788890701849 ; , s. 3078-3081
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Konferensbidrag (refereegranskat)abstract
- We present the development on an ultra-wideband (UWB) radar system and its signal processing algorithms for detecting human breathing and heartbeat in the paper. The UWB radar system consists of two (Tx and Rx) antennas and one compact CMOS UWB transceiver. Several signal processing techniques are developed for the application. The system has been tested by real measurements. .
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| 7. |
- Kildal, Per-Simon, 1951, et al.
(författare)
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Fundamental Limitations on Small Multi-Beam Antennas for MIMO Systems
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 2164-3342. - 9788890701849 ; , s. 329-331
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Konferensbidrag (refereegranskat)abstract
- The paper finds theoretical limitations with MIMO technology of higher order when space is limited. The results show that it is possible to achieve up to six independent identically distributed (i.i.d.) channels in rich isotropic multipath (RIMP) by combining different incremental sources to an incrementally small 6-port antenna. This means that we with incrementally small antennas can generate MIMO performance with maximum six data streams in RIMP (rank 6). We also show that it is possible to achieve completely isotropic full-spherical angular coverage by using an incrementally small 3-port antenna consisting of three orthogonal electric or magnetic dipoles. However, it is possible to get isotropic spatial coverage with 3 dB higher directivity in all directions by using a 6-port antenna consisting of both three orthogonal electric dipoles and three orthogonal magnetic dipoles, or alternatively a 6-port Huygens antenna consisting of 6 uncoupled Huygens sources. In random-LOS (having only a single angle of arrival) there will be a maximum of two data streams (rank 2) available, associated with two orthogonal polarizations. We show that both streams can be received with the 3-port incremental dipole antenna, and with 3 dB higher power with either of the 6-port antennas. The randomness of the angle of arrival in LOS is caused by the arbitrary orientation and location of the user-terminal.
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| 8. |
- Li, Hui, et al.
(författare)
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Analysis of SAR on flat phantom for different multi-antenna mobile terminals
- 2014
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Ingår i: European Conference on Antennas and Propagation (EuCAP), 2014. - 2164-3342. - 9788890701849 ; , s. 1989-1989
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Konferensbidrag (refereegranskat)abstract
- Evaluation of Specific Absorption Rate (SAR) for multiple antenna systems is becoming important, with the upcoming deployment of LTE-Advanced. In this work, the influence of different antenna locations and antenna types was investigated for stand-alone SAR and simultaneous SAR, to provide some guidelines for antenna design in multi-antenna handsets. For simultaneous SAR, different phase shifts between antenna ports were considered and the averaged SAR was used as a metrics for comparison. The SAR performances were evaluated in simulation for the body worn scenario, and different placements of the mobile handset, i.e., with either the screen or back side closer to the body, were studied.
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| 9. |
- Ludick, D. J., et al.
(författare)
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A comparison of domain decomposition techniques for analysing disjoint finite antenna arrays
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014. - 2164-3342. - 9788890701849 ; , s. 2411-2415
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Konferensbidrag (refereegranskat)abstract
- The purpose of this work is to present a quantitative comparison between three Method-of-Moments based domain decomposition techniques that are used for the analysis of large, disjoint finite antenna arrays. The methods considered are the Characteristic Basis Function Method, the Domain Green's Function Method, and a newly proposed improved version of the DGFM, i.e., the i-DGFM. The computational complexities of the techniques are compared in terms of runtime and memory usage. Both active and passive antenna arrays are considered.
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| 10. |
- Razavi, Seyed Ali, et al.
(författare)
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Design of 60GHz Planar Array Antennas Using PCB-based Microstrip-Ridge Gap Waveguide and SIW
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 2164-3342. - 9788890701849 ; , s. 1825-1828
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Konferensbidrag (refereegranskat)abstract
- A wideband 2×2-slot element for a 60 GHz antenna array is designed by making use of two double-sided printed circuit boards (PCBs). The upper PCB contains the four radiating cavity-backed slots backed by a substrate-integrated waveguide (SIW) cavity. The SIW cavity is excited by a coupling slot fed by a microstrip-ridge gap waveguide formed in the air gap between the upper and lower PCBs. The designed 2×2-slot element is considered in an infinite array environment. A sample 32×32 slot array aperture is simulated using infinite array approach and the relative bandwidth of 16% over 57-66GHz frequency range with the directivity of more than 38 dBi over the operating bandwidth is obtained. The simulations are verified by measurements on a smaller 4×4 slot array surrounded by dummy elements.
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