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- Alayon Glazunov, Andres
(author)
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Expansion of the Kronecker and Keyhole Channels Into Spherical Vector Wave Modes
- 2011
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In: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 10, s. 1112-1115
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Journal article (peer-reviewed)abstract
- In this letter, we provide additional results on the expansion of wireless channels into spherical vector wave multipole modes. We specialize our results to multiple-input-multiple-output (MIMO) channels with Kronecker-product structure of the correlation matrix: 1) the Kronecker channel, and 2) the Keyhole channel. We show that the Kronecker or Keyhole structure of the multimode channel matrix implies the corresponding structure in the MIMO channel matrix. Moreover, we show that the separability of the joint probability distribution functions of the angle of arrival (AoA) and the angle of departure (AoD), i.e., the independence between the AoAs and the AoDs for co- and cross-polarized components results in a Kronecker-product structure of the full-correlation matrix of the multimode matrix for both the Kronecker and the Keyhole channels.
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| 4. |
- Gruden, Mathias, et al.
(author)
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Measurements and Simulations of Wave Propagation for Wireless Sensor Networks in Jet Engine Turbines
- 2011
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In: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 10, s. 1139-1142
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Journal article (peer-reviewed)abstract
- In this letter, measurements and simulations of wave propagation inside a jet engine fan have been performed. The investigation was done using both EM simulations of different cases of propagation inside the engine and by measuring the corresponding cases inside a half-scale model of a jet engine fan. The average path loss was calculated, and the shapes of the fading distributions were extracted. The time between two consecutive fading dips was measured in the empirical part. Measurements were performed with engine speeds of both 30 and 60 rpm and were shown to be linearly scalable from 60 rpm to full speed of 10 000 rpm. The results showed an average path loss of about 55 dB. When scaling the measurements from 60 rpm to full-speed rotation of about 10 000 rpm, the fading was so severe that the time slot between consecutive fading dips was limited to 290 mu s.
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| 6. |
- Hallbjörner, Paul, 1966, et al.
(author)
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Low-Profile 77-GHz Lens Antenna With Array Feeder
- 2012
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In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 11, s. 205-207
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Journal article (peer-reviewed)abstract
- A 77-GHz lens antenna for automotive radar applications is presented. It consists of a feeder in the formof a 2 x 2 patch array etched from a single layer on a 100-mu m-thick substrate and a commercially available dielectric lens. Compared to previously published lens antennas, the presented design has the advantages of excellent electrical performance and a low profile in combination with a thin lens. Measurements of port impedance match and radiation patterns are presented. Beam tilt by lateral offset of the lens is demonstrated experimentally.
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| 7. |
- Hidén Rudander, Jacob, 1986, et al.
(author)
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Measurements of RFID Tag Sensitivity in Reverberation Chamber
- 2011
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In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 10, s. 1345 - 1348
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Journal article (peer-reviewed)abstract
- The reverberation chamber is now commonly accepted and used for fast and accurate performance evaluation of mobile phones and other wireless devices for in particular new systems such as LTE 4G and IEEE 802.11n Wi-Fi. In this letter, we describe a new methodology of measuring sensitivity of RFID tags in a reverberation chamber, and we show how the measurements time can be shortened by using the fact that the RFID tag behaves like an ideal threshold receiver. We then extend to tag population measurements that can be used to select the best tag among the many during the same measurement sequence.
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| 8. |
- Jamaly, Nima, 1979, et al.
(author)
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A Revisit to Spatial Correlation in Terms of Input Network Parameters
- 2012
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In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 11, s. 1342-1345
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Journal article (peer-reviewed)abstract
- An alternative compact formula in terms of input network parameters for calculation of envelope correlations is provided. The main advantage of this formula is that it can be simply modified to include cases of lossy structures and general cases of correlated nonuniform multipath environments. This formula is based on the open-circuit covariance matrix of the multiport antennas. The latter can be either estimated or quickly measured in a reverberation chamber, which removes the need for costly measurements of the embedded far field patterns.
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| 10. |
- Jamaly, Nima, 1979, et al.
(author)
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Compact Formulas for Diversity Gain of Two-Port Antennas
- 2010
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In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 9, s. 970-973
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Journal article (other academic/artistic)abstract
- Accuracy limitation in evaluation of diversity gains based on cumulative distribution function curves is highlighted. New devised closed-form formulas are provided for Selection Combining and Maximum Ratio Combining diversity schemes rendering diversity gain as a function of correlation and radiation efficiencies. Accuracy of these formulas is studied and verified by numerical simulations. These formulas take a central role for the cases when engineers are limited to a finite number of measured voltage samples at different ports to provide them with accurate calculation of ergodic diversity gain. This letter also reveals dependency of different diversity gains upon total embedded efficiencies of branches and underscores the significance of identical efficiencies of two-element terminals for their optimum performance in multipath environments. © 2010 IEEE.
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