Browsing by Subject "Refractive index"
Now showing items 1-20 of 28
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Conference Object
Analysis of an off-broadside zero beam-squinting leaky-wave antenna using metamaterials
(Institute of Electrical and Electronics Engineers Inc., 2016)It is shown that zero beam-squinting can be achieved in both series fed antenna arrays and leaky-wave antennas by employing two parallel-connected metamaterial transmission lines with equal positive group delays, but with ...
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Conference Object
Arbitrary length zero-phase substrate integrated coaxial lines using NRI-TL metamaterials
(Institute of Electrical and Electronics Engineers Inc., 2017)Arbitrary-length zero-degree phase-shifting lines are presented at X-band that are based on negative-refractive-index transmission-line (NRI-TL) metamaterials implemented in substrate integrated coaxial line (SICL) technology. ...
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Conference Object
A broadband balun using metamaterial phase-shifting lines
(2005)A 3-port device that converts a single-ended input to a differential output over a large bandwidth is presented. The balun comprises a Wilkinson divider, followed by a +90° negative-refractive-index (NRI) metamaterial (MM) ...
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Article
A broadband dual-mode monopole antenna using NRI-TL metamaterial loading
(2009)A printed monopole antenna is proposed which uses negative-refractive-index transmission-line (NRI-TL) metamaterial loading in order to achieve a broadband dual-mode operation. The metamaterial-loaded monopole supports a ...
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Article
A broadband series power divider using zero-degree metamaterial phase-shifting lines
(2005)A metamaterial 1:4 series power divider that provides equal power split to all four output ports over a large bandwidth is presented, which can be extended to an arbitrary number of output ports. The divider comprises four ...
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Article
A broadband Wilkinson balun using microstrip metamaterial lines
(2005)A metamaterial balun that converts a single-ended input to a differential output over a large bandwidth is presented. The device also exhibits excellent return loss, isolation, and through characteristics over the same ...
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Article
Carrier dynamics and conductivity of SnO 2 nanowires investigated by time-resolved terahertz spectroscopy
(2012)THz spectroscopy has been applied to investigate the photo-induced and intrinsic conductivity in SnO 2 nanowires using the Drude-Smith model. The refractive index of the nanowires was found to decrease from 2.4 to 2.1 with ...
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Article
Carrier dynamics and conductivity of SnO 2 nanowires investigated by time-resolved terahertz spectroscopy
(2012)THz spectroscopy has been applied to investigate the photo-induced and intrinsic conductivity in SnO 2 nanowires using the Drude-Smith model. The refractive index of the nanowires was found to decrease from 2.4 to 2.1 with ...
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Article
A compact and low-profile metamaterial ring antenna with vertical polarization
(2005)A compact (λ 0/11 footprint) and low-profile (λ 0/28 height) metamaterial ring antenna is proposed using two metamaterial unit cells. Each constituent unit cell consists of negative-refractive-index (NRI) microstrip ...
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Article
Compact linear lead/lag metamaterial phase shifters for broadband applications
(2003)A compact one-dimensional phase shifter is proposed using alternating sections of negative refractive index (NRI) metamaterials and printed transmission lines (TL). The NRI metamaterial sections consist of lumped element ...
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Article
A Compact Multiband Printed Dipole Antenna Loaded with Two Unequal Parallel NRI-TL Metamaterial Unit Cells
(2015)A negative-refractive-index transmission-line (NRI-TL) metamaterial-loaded dipole antenna is proposed, which has a fully printed configuration and exhibits multiband performance. The antenna consists of a conventional ...
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Conference Object
Compact, linear, lead/lag phase shifters using negative refractive index metamaterials
(2003)A new type of phase shifter using cascaded sections of NRI metamaterials and PRI transmission lines is proposed, which offers some significant advantages over conventional delay lines. The phase shifter is compact in size, ...
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Article
A CPS leaky-wave antenna with reduced beam squinting using NRI-TL metamaterials
(2008)A reduced beam-squinting printed leaky-wave antenna (LWA) is proposed, comprising cascaded negative-refractive-index transmission-line (NRI-TL) metamaterial unit cells. Each NRI-TL unit cell is implemented in co-planar ...
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Article
Effects of Ge concentration, boron co-doping, and hydrogenation on fiber bragg grating characteristics
(2005)In this paper, we compare photosensitivity, refractive-index modulation depth, spectral bandwidth, and excess loss through the inscription of fiber Bragg gratings in unloaded and hydrogen-loaded fibers with low- or ...
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Conference Object
Enabling electromagnetic applications of negative-refractive-index transmission-line metamaterials part II
(Institute of Electrical and Electronics Engineers Inc., 2004)The 1-Dimensional (1-D) metamaterial phase-shifting lines presented in [1] can be used to develop compact and broadband, non-radiating, metamaterial feed-networks for antenna arrays. These can be used to replace conventional ...
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Article
A folded-monopole model for electrically small NRI-TL metamaterial antennas
(2008)An improved model for analyzing electrically small NRI-TL antennas is proposed, that highlights the methods that enable these antennas to offer a good impedance match and a high radiation efficiency compared to previously ...
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Article
Large ultrafast optical nonlinearities in As-rich GaAs
(1994)The measurement of large Ultrafast bandgap-resonant optical nonlinearities in As-rich samples of GaAs that have been grown at low temperatures is reported. Light-induced refractive index changes of magnitude greater than ...
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Article
Multiband compact printed dipole antennas using NRI-TL metamaterial loading
(2012)A compact, fully-printed negative-refractive-index transmission-line (NRI-TL) metamaterial-loaded dipole antenna is proposed, which exhibits multiband resonant characteristics that are not harmonically related. The multiband ...
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Conference Object
Negative-refractive-index transmission-line metamaterial-loaded dipole antennas
(2012)Several compact, fully-printed negative-refractive-index transmission-line (NRI-TL) metamaterial-loaded dipole antennas are proposed. The antennas achieve multi-band behaviour by loading a host dipole antenna with series ...
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Conference Object
Negative-refractive-index transmission-line metamaterials and enabling electromagnetic applications
(2004)The negative-refractive-index (NRI) metamaterials, for which the permittivity and permeability are simultaneously negative, were discussed. The results for two RF/Microwave devices and structures, based on transmission-line ...