| 1. |
- Glazunov, Andres Alayon, 1969, et al.
(författare)
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Devising a Horizontal Chamber Array for Automotive OTA Tests in Random Line-Of-Sight
- 2016
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Ingår i: International Symposium on Antennas and Propagation (ISAP), Hobart, Australia, 9-12 November, 2015. ; , s. Art. no. 7447285-
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose an approach to design a horizontal array antenna to reduce the uncertainty of reference measurements in Random Line-Of-Sight Over-The-Air testing in anechoic chambers. The main focus is on wireless communications testing to and from automotive vehicles. The proposed procedure allows to determine the size, the spacing and the number of elements of a horizontal array antenna resulting in an absolute error less than 1 dB. The analysis is based on presenting the output of the ideal digital threshold receiver model of the device under test as a Probability of Detection curve.
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| 2. |
- Glazunov, Andres Alayon, 1969, et al.
(författare)
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Impact of the Spatial User Distribution on the Coverage Antenna Pattern of Maximum Ratio Combining in Random Line-Of-Sight
- 2015
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Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
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Konferensbidrag (refereegranskat)abstract
- In this paper we investigate the impact of the spatial user distribution on the Maximum Ratio Combining (MRC) of the output signals from an ideal 4-port antenna. The antenna consists of four elementary Huygens sources operating in Random Line-Of-Sight (RLOS). The antenna is assumed to be wall-mounted. Two specific scenarios for the user distribution are considered, i.e., the 3D hemisphere and a rectangular prism emulating a corridor or a rectangular room. We present simulation results in terms of the cumulative distribution functions corresponding to the resulting polarisation and pattern diversity of 1-bitstream and the corresponding coverage radiation pattern of the 4-port antenna system. We also show that there is an antenna arrangement that maximizes the diversity gain that will be different for different spatial distributions of users.
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| 3. |
- Lehne, Per H., et al.
(författare)
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Analyzing smart phones' 3D accelerometer measurements to identify typical usage positions in voice mode
- 2016
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Ingår i: 10th European Conference on Antennas and Propagation, EuCAP 2016; Davos; Switzerland; 10 April 2016 through 15 April 2016. - 2164-3342. - 9788890701863 ; , s. Art. no. 7481895-
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Konferensbidrag (refereegranskat)abstract
- Smart phone sensors provide new possibilities to understand how devices are actually used and handled in real-life situations. Such information can possibly be used to design better handsets, but also to improve network performance. For example, the radiated performance of a wireless device depends on its orientation and position relative to the user. Hence, knowing realistic handset usage plays a major role in the Over-The-Air characterization of antennas and wireless devices in general. This paper presents an analysis of usage positions for voice service. A simplified statistical model based on data collected from devices acceleration sensors is presented. The analysis shows interesting results from which we can identify some typical ways the user is handling the phone when in a voice conversation. Our analysis shows clear differences of the orientation of the handset when used with a handsfree set and when not.
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| 4. |
- Lehne, Per Hjalmar, et al.
(författare)
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Measuring user-induced-randomness to evaluate smart phone performance in real envi-ronments
- 2015
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Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
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Konferensbidrag (refereegranskat)abstract
- The radiated performance of a wireless device depends on its orientation and position relative to the user. In addition, the antenna performance is different on different devices and it depends on the device model. Hence, to understand the impact of the users behaviour on the device antenna and the resulting network performance an investigation of the device usage and signal quality is of high importance. This paper presents a first analysis of the orientation usage of wireless devices based on data gathered from 5 smart phones over a period of more than two months. The data was obtained from the built-in sensors in the phone, and includes angles of orientation, information about signal quality and the connected network Some interesting trends regarding typical orientations of the phone are presented for both voice and data services. We believe that data of this type has the potential to be used for optimizing the device and the network performance, e.g., when the data is correlated with the experienced channel quality.
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| 5. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Design of micromachined ridge gap waveguides for millimeter-wave applications
- 2011
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Ingår i: Procedia Eng.. - : Elsevier BV. ; 25, s. 519-522
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Konferensbidrag (refereegranskat)abstract
- The ridge gap waveguide is a new transmission line for millimeter-wave applications. Traditionally, rectangular waveguides are used for those applications due to their low loss. However their fabrication requires precision machining, very good electrical contact and alignment between two joining mechanical parts. Ridge gap waveguides can obtain similar performance without requiring conductive sidewalls and this provides more freedom during the fabrication and assembly process as the structure is no longer sensitive to small gaps between the side walls and the upper lid. The ridge gap waveguide has already been validated for 10-20 GHz using conventional fabrication methods. The ridge gap waveguide prototypes presented in this paper are designed to work in the frequency region between 210 and 340 GHz, and fabricated using MEMS technology. MEMS technology provides fabrication precision of the structures and thus opens the path for high-frequency components.
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| 6. |
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| 7. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Micromachined Ridge Gap Waveguide and Resonator for Millimeter-Wave Applications
- 2012
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Ingår i: Sensors and Actuators, A: Physical. - : Elsevier BV. - 0924-4247 .- 1873-3069. ; 186, s. 264-269
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Tidskriftsartikel (refereegranskat)abstract
- The ridge gap waveguide is a fundamentally new high-frequency waveguide. It does not need any electrical contact between the split blocks which gives it an advantage compared to the rectangular waveguide which is the standard today. These waveguides are conventionally fabricated by milling, although above 100 GHz milling is not adequate anymore. MEMS technology on the other hand, can offer high-precision fabrication and thus opens the path for new types of high-frequency components. In this paper both a ridge gap waveguide and a ridge gap resonator have been fabricated for the frequencies 220–325 GHz using MEMS technology. Support packages have been designed to enable device measurements. Simulations show that the reflection coefficient for the ridge gap waveguide is below −15 dB between 240 and 340 GHz. Two resonance peaks were measured at the frequencies 234 GHz and 284 GHz for the ridge gap resonator with unloaded Q-values of 336 and 527 respectively. Both the waveguide and resonator have the potential to obtain similar performances as the rectangular waveguide without strict requirement on electrical contact, allowing simplified fabrication and assembly technique.
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| 8. |
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| 9. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
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Initial Measured OTA Throughput of 4G LTE Communication to Cars with Roof-Mounted Antennas in 2D Random-LOS
- 2016
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Ingår i: International Symposium on Antennas and Propagation (ISAP), Hobart, Australia, 9-12 November, 2015. ; , s. Article no 7447419-
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Konferensbidrag (refereegranskat)abstract
- We present initial Over-The-Air (OTA) throughput measurements of an LTE device in a Volvo XC90 car with roof-mounted antennas. The measurements were performed ina semi-anechoic chamber and only in the horizontal plane. The throughput results are presented as a probability of detection (PoD) in 2D Random Line-Of-Sight (Random-LOS) with fixed polarization of the antenna at the base station side. Two carmounted antennas were measured: a wideband two-port sharkfin type antenna in SISO and SIMO receive diversity-mode, and a narrowband monopole antenna. The PoD curves clearly show the expected performance improvements due to the antenna diversity.In addition, the Random-LOS measurements made it possible to discover potential for improvements of the tested antennas.
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| 10. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
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Investigation of mode stirring with plate on platform in a reverberation chamber
- 2015
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Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
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Konferensbidrag (refereegranskat)abstract
- The accuracy of the reverberation chamber has been investigated when mode stirring is performed with a plate placed on a rotatable platform, i.e., plate-on-platform stirring. The accuracy and scanning volume of the platform plate are then compared to the original mode stirring plates that are moving alongside two walls. The results are also compared to physical theoretical models. The mode stirring with a plate on the platform provides STD of the measurements that are a factor 2 worse than with the original plate and platform stirring of the chamber. Still, this is good enough for accurate measurements above 2 GHz, provided the AUT is also located on the platform.
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