Deepti Das, Krishna; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Electronics Letters, August , 2008)
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Abstract:
An ultra-wideband (UWB) printed slot antenna, suitable for integration with the printed circuit board (PCB) of a wireless universal serial-bus (WUSB) dongle is presented. The design comprises a near-rectangular slot fed by a coplanar waveguide printed on a PCB of width 20 mm. The proposed design has a large bandwidth covering the 3.1-10.6 GHz UWB band, unaffected by the ground length, and omnidirectional radiation patterns. A linear phase response throughout the band further confirms its suitability for high-speed wireless connectivity.
Deepti Das, Krishna; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Wiley InterScience, June , 2009)
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Abstract:
A compact ultra-wideband (UWB) printed slot antenna is described, suitable for integration with the printed circuit board (PCB) of a wireless, universal, serial-bus dongle. The design comprises of a near-rectangular slot fed by a coplanar waveguide (CPW) printed on a PCB of size 20 × 30 mm2. It has a large bandwidth covering the 3.1–10.6 GHz UWB band, with omnidirectional radiation patterns. Further, a notched band centered at 5.45 GHz wireless local area network bands is obtained within the wide bandwidth by inserting a narrow slot inside the tuning stub. Details of the antenna design are described, and the experimental results of the constructed prototype are presented. The time domain studies on the antenna shows a linear phase response throughout the band except at the notched frequency. The transient analysis of the antenna indicates very little pulse distortion confirming its suitability for high speed wireless connectivity.
Hyunkieu,Yang; Sangseol,Lee(Microwave and Optical Technology Letters, December 5, 2001)
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Abstract:
The cutoff wavenumbers of higher order modes in circular
eccentric guides are computed with the variational analysis combined
with a conformal mapping. A conformal mapping is applied to the
variational formulation, and the variational equation is solved by the
finite-element method. Numerical results for TE and TM cutoff
wavenumbers are presented for different distances between the centers
and ratio of the radii. Comparisons with numerical results found in the
literature validate the presented method
Pedicle screw insertion technique has made revolution in the surgical treatment of spinal fractures and spinal disorders. Although X- ray fluoroscopy based navigation is popular, there is risk of prolonged exposure to X- ray radiation. Systems that have lower radiation risk are generally quite expensive. The position and orientation of the drill is clinically very important in pedicle screw fixation. In this paper, the position and orientation of the marker on the drill is determined using pattern recognition based methods, using geometric features, obtained from the input video sequence taken from CCD camera. A search is then performed on the video frames after preprocessing, to obtain the exact position and orientation of the drill. An animated graphics, showing the instantaneous position and orientation of the drill is then overlaid on the processed video for real time drill control and navigation
Lethakumary,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
Sreedevi, Menon K; Lethakumary,B; Mohanan, P; Bijumon, P V; Sebastian,M T(Microwave and Optical Technology Letters, August 20, 2004)
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Abstract:
A broadband cylindrical dielectric resonator antenna
(DRA) energized with an L-strip feed is presented The novel exciting
technique achieves a 2:1 VSWR bandwidth of 18%. The variation of
bandwidth for different feed parameters is also studied
The design and development of an L-band printed dipole antenna.
optimized for wide-band applications near first resonance, is reported.
This design has achieved more than 48% impedance bandwidth
(VSWR 2:1), without degrading its overall radiation efficiency
Sarin, V P; Nisha, Nassar; Deepu, V; Aanandan,C K; Mohanan, P; Vasudevan, K(Antennas and Wireless Propagation Letters, IEEE, 2009)
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Abstract:
A simple electromagnetically coupled wideband printed microstrip antenna having a 2:1 VSWR bandwidth of 38% covering the 5.2/5.8-GHz WLAN, HIPERLAN2, and HiSWANa communication bands is presented. The large bandwidth is obtained by adding a rectangular metal strip on a slotted square microstrip antenna. The antenna occupies an overall dimension of 42 times 55 times 3.2 mm3 when printed on a substrate of dielectric constant 4. It exhibits good radiation characteristics and moderate gain in the entire operating band. Details of the design along with experimental and simulation results are presented and discussed.
Suma,M N; Bybi, P C; Mohanan, P(Wiely, May , 2006)
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Abstract:
A planar monopole antenna suitable for broadband wireless communication is designed and developed. With the use of a truncated ground plane, the proposed printed monopole antenna offers nearly 60% 2:1 VSWR bandwidth and good radiation characteristics for the frequencies across the operating band. A parametric study of the antenna is performed based on the optimized design, and a prototype of the antenna suitable for 2.4-GHz WLAN application is presented. The antenna can be easily integrated into wireless circuitry and is convenient for application in laptop computers.
Lethakumary,B; Sreedevi, Menon K; Aanandan,C K; Mohanan, P(Microwave and Optical Technology Letters, April 5, 2003)
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Abstract:
An electromagnetically coupled T-shaped microstrip feed
used to enhance the impedance bandwidth of a rectangular microstrip
antenna is reported. The proposed antenna offers a 2:1 VSWR bandwidth
of -36% with an increase in gain of 0.8 dB
Sreedevi, Menon K; Lethakumary,B; Vasudevan, K(Microwave and Optical Technology Letters, November 5, 2002)
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Abstract:
Bandwidth enhancement of a rectangular microstrip
antenna using a T-shaped microstrip feed is explored in this paper.
A 2:1 VSWR impedance bandwidth of 23% is achieved by employing
this technique. The far-field patterns are stable across the pass band.
The proposed antenna can be used conveniently in broadband communications
Mathew, K T; Stephen,D S; Aanandan,C K; Mohanan, P; K G Nair(Department of Electronics, May 12, 1994)
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Abstract:
A trapezoidal strip grating surface that eliminates specular
reflections almost over the entire X -band frequency range for TM
polarization is reported This new grating structure overcomes the
bandwidth limitation of conventional rectangular strip grating surfaces