The design and implementation of a novel asymmetric coplanar
waveguide (ACPW ) band rejection filter using defected ground
structure ( DGS) is presented . The proposed ACPW DGS technology
provides band gap characteristics with only one cell in the lateral
ground plane . The equivalent circuit model of the proposed DGS
unit section is described . Measurements of ACPW DGS showed good
agreement with simulation and the proposed model
Jayaraj, M K(Institute of Materials Engineering Australasia Ltd, 2005)
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Abstract:
ZnGa2O4 spinel is a promising new UV transparent electronic conductor. Enhancing the electrical conductivity of this
potential oxide phosphor can make it a promising transparent conducting oxide. In this paper, we have investigated the
effects of processing and doping on the conductivity of semiconducting ZnGa2O4, particularly thin films. Crystalline
zinc gallate thin films have been deposited on fused quartz substrates employing the pulsed laser deposition (PLD)
technique at room temperature for an oxygen partial pressure of 0.1 Pa (0.001mbar). The films were found to be UV
transparent, the band gap of which shifted to 4.75eV on hydrogen annealing. The band gap of the oxygen stoichiometric
bulk powder samples (4.55eV) determined from diffuse reflection spectrum (DRS) shifted to 4.81eV on reduction in a
hydrogen atmosphere. The electrical conductivity improved when Sn was incorporated into the ZnGa2O4 spinel. The
conductivity of ZnGa2O4:Sn thin films was further improved on reduction.
Gijo,Augustin; Shynu,S V; Aanandan,C K; Mohanan,P; Vasudevan,K(Microwave and Optical Technology Letters, April 20, 2005)
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Abstract:
An innovative phaseshifterless, wideband, micrustrip
leaky-wave antenna with an electronically steerable dual-pencil-beam
pattern in the H-plane is presented. The log-periodic geometry of the
leaky slots of the antenna results in a wide bandwidth of 25.19%. The
Jan beam can he steered up to 14° over the wide resonating band of the
anteww. The beam is also steerable at a fixed frequency. by reactivelty
loading the slots and a maximum steering angle of about 14° is ohserved.
for different capacitor values with an improved bandwidth of
33 _i%. This concept is studied using passive components but it can be extended to varactors
Bijumon,P V; Sreedevi,Menon K; Suma,M N(Microwave and Optical Technology Letters, November 5, 2005)
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Abstract:
rectangular low-density, high-permittivity dielectric
resona or antenna (DRA) excited by T-shaped microstrip feed offering a
2:1 VSWR bandwidth of -22% at 2.975 GHz is reported. The design
methoaology and experimental results of the antenna are discussed. The
excellent gain and radiation performance of the proposed antenna
project: it as a potential candidate for telecommunication applications
Sreedevi,Menon K; Vasudevan,K; Aanandan,C K; Mohanan,P(Microwave and Optical Technology Letters, September 20, 2005)
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Abstract:
Propagation of electromagnetic waves through a microstrip
line with 2D electromagnetic baud gap (EBG) structures of different
geometrical shapes in the ground plane is investigated in this paper.
Using transmission-line theory, the design equations for EBG structures are calculated. The measured, numerical. and simulated results are in
gone) agreement
Haddud,T A; Al-Mansoori,M H; Zamzuri,A K; Shaharudin,S; Abdullah,M K; Mahdi,M A(Microwave and Optical Technology Letters, April 20, 2005)
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Abstract:
In this paper, the generation of a multiwavelength laser
source from a Brillouin -Erbium fiber laser in the long wavelength band
(L-band) region is experimentally demonstrated. The proposed laser
system utilizes a Fabrv-Perot cavity formed by fiber-loop mirrors.
Twenty-four lines of Brillouin-Stokes with line spacings of 10 GHz are
obtained in the L-band region
Qiang,Gao; Yan,Yin; Dun-Bao,Yan; Nai,Chang Yuan(Microwave and Optical Technology Letters, November 5, 2005)
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Abstract:
A navel ultra-thin radar-absorbing material (RAM) using
metanwterials is presented and the absorption performance is examined.
Due to the high-impedance property of the metamalerials. the thickness
of the RAM is about several tenths of the center wavelength of the absorption
band, which is considerably thinner than conventional absorbers.
The absorption bandwidth of the RAM is about several hundred
megahertz
Lethakumari,B; Sreedevi,Menon K; Priya,Francis; Aanandan,C K; Mohanan,P(Microwave and Optical Technology Letters, January 20, 2005)
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Abstract:
In this paper, we introduce a novel feeding technique for
bandwidth enhancement of a rectangular microstrip antenna This antenna
offers an impedance bandwidth of 22% without degrading the effciencv.
The effect of the feed parameters upon patch characteristics
such as resonant frequency, impedance bandwidth, and radiation pattern are studied in detail. The experimental results are verified using the
FDTD results