| 1. |
- Alayon Glazunov, Andres
(författare)
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Expansion of the Kronecker and Keyhole Channels Into Spherical Vector Wave Modes
- 2011
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 10, s. 1112-1115
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Banik, Biddut Kumar, 1978, et al.
(författare)
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Microwave S-parameter Characterization of an Antenna-Coupled Catadioptric Lens
- 2009
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 8, s. 1299-1301
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Tidskriftsartikel (refereegranskat)abstract
- The focusing property of a bow-tie antenna coupled catadioptric lens is studied experimentally using a vector measurement setup. The results show that the lens-antenna provides short-range focusing. Furthermore, the return loss of the lens-antenna was determined numerically and confirmed experimentally from 1 GHz to 10 GHz. The lens-antenna provides 60% bandwidth (VSWR ≤ 2) centered at 6 GHz. Finally, the lens-antenna was employed to detect and locate buried objects and results are presented.
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| 3. |
- Bencivenni, Carlo, 1986, et al.
(författare)
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Aperiodic Switched Array for Line-of-Sight MIMO Backhauling
- 2018
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 17:9, s. 1712-1716
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Tidskriftsartikel (refereegranskat)abstract
- A switchable aperiodic array solution is proposed to increase the minimum channel capacity of a multiple-input-multiple-output (MIMO) backhauling system over an extended line-of-sight communication range. The objective is to propose a low-complexity design solution that is cost-effective in regard to the manufacturing, installation, and its design process. It is shown that by adding only one switch and one auxiliary antenna per base station, a 4 × 4 MIMO system can be realized that is capable of minimizing the capacity loss that both regular and aperiodic arrays suffer from as a function of the link distance.
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| 4. |
- Bencivenni, Carlo, 1986, et al.
(författare)
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Design of Maximally Sparse Antenna Arrays in the Presence of Mutual Coupling
- 2015
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1548-5757 .- 1536-1225. ; 14, s. 159-162
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Tidskriftsartikel (refereegranskat)abstract
- An optimization framework is proposed that combines electromagnetic field simulations with an iterative l(1)-norm minimization procedure to synthesize optimally sparse antenna arrays. The proposed approach overcomes the limitation of design methodologies that assume idealized antenna elements employing equal (isolated or isotropic) element patterns, as these yield suboptimal solutions when the antenna mutual coupling effects cannot be ignored. The latter is demonstrated for arrays of relatively strongly coupled dipole radiators.
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| 5. |
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| 6. |
- Castillo Tapia, Pilar, et al.
(författare)
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V-Band Monolithic Additive-Manufactured Geodesic Lens Array Antenna
- 2023
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1225 .- 1548-5757. ; 22:10, s. 2527-2531
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Tidskriftsartikel (refereegranskat)abstract
- Fully metallic geodesic lens antennas are popular for millimeter-wave band applications due to their simplicity, robustness, and low loss. Here, we report the experimental results of a geodesic lens array antenna, which was specifically designed to be additive-manufactured in one single piece using laser powder-bed fusion (LPBF). LPBF in aluminum alloy AlSi10Mg is able to produce high conductivity and relatively low surface roughness, so the antenna is highly directive and efficient. In addition, LPBF increases the robustness of the design since the lens array is monolithic, i.e., the risks associated with the assembly, including misalignments and undesired air gaps between pieces, are totally eliminated.
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| 7. |
- Cheng, Shi, et al.
(författare)
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Printed slot planar inverted cone antenna for ultrawideband applications
- 2008
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 7, s. 18-21
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Tidskriftsartikel (refereegranskat)abstract
- A novel ultrawideband (UWB) printed wide-slot antenna is presented. The design is based on the planar inverted cone antenna (PICA), introduced by Suh. The presented design comprises PICA-like structures, etched from a double-layer substrate. Compared to the original PICA, it is lower in profile, more compact and maintains comparable performance. A prototype integrated in a printed circuit board and fed by a microstrip line is fabricated and measured. The results show that the proposed antenna provides at least 13:1 impedance bandwidth at 10-dB return loss.
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| 8. |
- Cheng, Shi, et al.
(författare)
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Switched beam antenna based on RF MEMS SPDT switch on quartz substrate
- 2009
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 8, s. 383-386
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Tidskriftsartikel (refereegranskat)abstract
- This letter demonstrates a 20-GHz radio frequency microelectromechanical system (RF MEMS)-based electrically switchable antenna on a quartz substrate. Two quasi-Yagi antenna elements are monolithically integrated with a single-pole double-throw (SPDT) MEMS switch router network on a 21 mm x 8 mm chip. Electrical beam steering between two opposite directions is achieved using capacitive MEMS SPDT switches in the router. Port impedance and radiation patterns are studied numerically and experimentally. Measured results show that the switched beam antenna features a 27% impedance bandwidth (S-11 = -10 dB), a gain of 4.6 dBi, and a front-to-back ratio of 14 dB at 20 GHz when the control voltage is applied to one of the switch pairs of the SPDT switch.
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| 9. |
- Conway, G. A., et al.
(författare)
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In Situ Measurement of UHF Wearable Antenna Radiation Efficiency Using a Reverberation Chamber
- 2008
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1548-5757 .- 1536-1225. ; 7, s. 271-274
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Tidskriftsartikel (refereegranskat)abstract
- The radiation efficiency and resonance frequency of five compact antennas worn by nine individual test subjects was measured at 2.45 GHz in a reverberation chamber. The results show that, despite significant differences in body mass, wearable antenna radiation efficiency had a standard deviation less than 0.6 dB and the resonance frequency shift was less than 1% between test subjects. Variability in the radiation efficiency and resonance frequency shift between antennas was largely dependant on body tissue coupling which is related to both antenna geometry and radiation characteristics. The reverberation chamber measurements were validated using a synthetic tissue phantom and compared with results obtained in a spherical near field chamber and finite-difference time-domain (FDTD) simulation.
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| 10. |
- Du, Yijun, et al.
(författare)
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Design of Sharp Roll-Off Band Notch with Fragment-Type Pattern Etched on UWB Antenna
- 2018
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 17:12, s. 2404-2408
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Tidskriftsartikel (refereegranskat)abstract
- Fragment-type etch patterns are proposed and designed on ultra-wideband planar antenna to acquire sharp roll-off band notch. Multi-objective evolutionary algorithm is applied to achieve the optimization searching of the best fragment-type etch pattern by setting multiple objectives to acquire the exact notched band and challenge the roll-off criterion (ROC) of band notch. Efficiency of the design can be improved by properly presetting slits on the patch radiator. For demonstration, designs with different slit presetting are implemented and tested. With single slit preset, band notch of ROC=0.72 at the WLAN band ranging from 5.15 GHz to 5.85GHz is acquired.
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