| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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| 5. |
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| 6. |
- Hallbjörner, Paul, et al.
(författare)
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Broadband Space-Time Measurements in Reverberation Chamber Including Comparison With Real Environment
- 2009
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 8, s. 1111-1114
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Tidskriftsartikel (refereegranskat)abstract
- Spatial variations of the broadband time-domain impulse response in a reverberation chamber are studied experimentally. The goal is to introduce the technique as a means for characterizing reverberation chambers and to demonstrate typical results and the information that can be extracted. Similar measurements are performed in a lab room for comparison. The results provide new insights regarding the signal environment inside a reverberation chamber and how it compares to real-life environments. The minimum number of signal paths in the chamber is calculated based on the spatial and temporal resolutions used in the characterization.
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| 7. |
- Hallbjörner, Paul, et al.
(författare)
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Circularly polarized traveling-wave array antenna with novel microstrip patch element
- 2007
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 6, s. 572-574
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Tidskriftsartikel (refereegranskat)abstract
- A traveling-wave microstrip array antenna with circular polarization in presented. It uses a novel circularly polarized dual-feed radiating element. The element is a square microstrip patch with a chamfered corner. It is fed by microstrip lines, so radiating element and feed lines can be realized in a single layer. A five-element array is designed and built. Measured performance is presented.
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| 8. |
- Hallbjörner, Paul, et al.
(författare)
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Modified planar inverted code antenna for mobile communication handsets
- 2007
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 6, s. 472-475
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Tidskriftsartikel (refereegranskat)abstract
- The planar inverted cone antenna (PICA) is an antenna type that shows remarkably wideband performance. In its basic configuration, it is mounted on an infinite ground plane, and protrudes lambda/4 above it. This letter presents a study of the possibilities of integrating a PICA in a mobile terminal handset by modifying the ground plane and the radiating element. Port impedance and radiation performance are studied in both simulations and measurement.
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| 9. |
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| 10. |
- Li, Hui, et al.
(författare)
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A Compact Planar MIMO Antenna System of Four Elements With Similar Radiation Characteristics and Isolation Structure
- 2009
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1225 .- 1548-5757. ; 8, s. 1107-1110
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Tidskriftsartikel (refereegranskat)abstract
- A compact planar multiple-input-multiple-output (MIMO) antenna system of four elements with similar radiation characteristics is proposed for the whole 2.4-GHz WLAN band. It consists of two proximity-coupled fed microstrip square ring patch antennas and two lambda/4 microstrip slot antennas of the same linear polarization. These two types of antennas are printed on different sides of the substrate to reduce mutual coupling. With a novel isolation structure etched on the ground plane of the FR4 substrate, high port isolation (below -25 dB) and good MIMO performance are achieved. The overall lateral size of the MIMO system is only 0.64 lambda X 0.48 lambda, and good impedance matching (S11 < 10 dB) is achieved across the operating band for all the antenna elements. Full spherical radiation patterns are measured for the MIMO system, showing similar radiation characteristics, and the gains are above 2.3 dB across the operating band.
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