A compact, dual band coplanar waveguide fed modified T-shaped uniplanar antenna is presented. The antenna has resonances at 1.77 and 5.54 GHz with a wide band from 1.47–1.97 GHz and from 5.13–6.48 GHz with an impedance bandwidth of 34% and 26%, respectively. Also the antenna has an average gain of 3 dBi in lower band and 3.5 dBi in higher band with an average efficiency of 90%.
Design of a compact dual frequency microstrip antenna
is presented. The structure consists of a slotted circular patch with
a dielectric superstrate. The superstrate,not only acts as a radome,
but improves the bandwidth and lowers the resonant frequency also.
The proposed design provides an overall size reduction of about 60%
compared to an unslotted patch along with good efficiency,gain
and bandwidth. The polarization planes at the two resonances are
orthogonal and can be simultaneously excited using a coaxial feed.
Parametric study of this configuration showed that the frequency ratio
of the two resonances can be varied from 1.17 to 1.7 enabling its
applications in the major wireless communication bands like AWS,
DECT,PHS,Wi.Bro, ISM,and DMB. Design equations are also
deduced for the proposed antenna and validated.
Deepti Das, Krishna; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Electronics Letters, August 3, 2006)
[+]
[-]
Abstract:
Design of a dual linearly-polarised microstrip patch antenna, excited
by two orthogonal microstrip feed lines, is presented. A reduction in
patch size of 35% is obtained when compared to a square patch
operating at the same frequency. The polarisations are oriented at +45
and - 45 with an isolation of more than 36 dB between the ports.
Unlike earlier designs, the proposed structure provides better gain.
Aanandan,C K; Mohanan, P; Vasudevan, K; Shynu, S V; Gijo,Augustin(Department of Electronics, 2004)
[+]
[-]
Abstract:
A novel design of a computer electronically reconfigurable dual frequency dual polarized single feed hexagonal slot loaded microstrip antenna in L-band is introduced in this chapter. pin diodes are used to switch the operating frequencies considerably without much affecting the radiation characteristics and gain. the antenna can work with a frequency ratio varying in the wide range from 1.2 to 1.4. the proposed design has an added advantage of size reduction up to 72.21% and 46.84% for the two resonating frequencies compared to standard rectangular patches. the design also gives considerable bandwidth of up to 2.82% and 2.42 % for the operating frequencies.
Manju,Paulson; Sona,Kundukulam O; Aanandan,C K; Mohanan, P; Vasudevan, K(Microwave and Optical Technology Letters, October 28, 2002)
[+]
[-]
Abstract:
An arrow-shaped microstrip antenna with a pair of narrow
slots embedded near the non-radiating edges gives wide impedance bandwidth.
The experimental and simulated (!E3D) results show that antenna
bandwidth is -3.5 times that of a conventional patch with the added advantage
of reduced antenna size. The radiation characteristics are found to he uniform throughout the operating band
Mridula, S; Shameena, V A; Aanandan,C K; Mohanan, P; Vasudevan, K; Jacob, S(IEEE, September , 2011)
[+]
[-]
Abstract:
A Coplanar waveguide fed compact planar
monopole antenna with a modified ground plane is presented.
Measured and simulated results reveal that the antenna operates
in the Ultra Wide Band with almost constant group delay
throughout the band. Developed design equations of the antenna
are validated for different substrates. Time domain performance
of the antenna is also discussed in order to assess its suitability
for impulse radio applications
Description:
General Assembly and Scientific Symposium, 2011 XXXth URSI
Dongsheng,Qi; Binhong,Li; Yabin,Zhang; Haitao,Liu(Microwave and Optical Technology Letters, February 3, 2004)
[+]
[-]
Abstract:
A novel compact single-layer dual frequency microstrip
antenna which uses an H-shaped geometry with two U-shaped slots embedded
near the radiation edges, is presented. By changing the design parameters, the lower and higher resonant frequencies can be controlled
easily, and a range of frequency ratios (1.716-2.363) can be
obtained in this design. For the two operating frequencies of the proposed
antenna, the same polarization planes and broadside radiation
patterns are achieved. Compared to the regular dualfrequency patch
antenna, this antenna can realize a significant size reduction
Thomas, Paulbert; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Wiley InterScience, October , 2010)
[+]
[-]
Abstract:
Design of a compact microstrip-fed ultra-wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni-directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 × 30 mm2 on FR4 substrate with permittivity 4.4.
A compact single –feed multiband planar antenna configuration
Suitable for GPS, DCS. 2.4/5.8 GHz WLAN applications are presented.
The antenna has dimensions 38 x 3 x 1.6 mm and offers good
radiation and reflection characteristics in the above frequency bands.
The antenna has a simple geometry and can be easily fed using a 50
coaxial probe
Mohanan, P; Raj,R K; Joseph,M; Paul,B(Department of Electronics, March 17, 2000)
[+]
[-]
Abstract:
A compact single - feed muttiband planar antenna configuration suitable
for GPS, DCS. 2.4/5.8 GHz WLAN applications is presented.
The antenna has dimensions 38 x 3 x 1.6 mm and offers good
radiation and reflection characteristics in the above frequency bands.
The antenna has a simple geometry and can be easily fed using a 50
coaxial probe.
A dual band RFID applications in 800 900
MHz and 2400 MHz band is presented. The
Asymmetric Coplanar Strip (ACS) fed antenna
consists of inverted L shaped monopole with a
capacitive loading to provide necessary impedance
matching and current distribution. The antenna has
wide bandwidth from 790 MHz tol050 MHz and
from 2350 MHz to 2640 MHz coving the RFID UHF
and Microwave frequencies. The uniplanar antenna
having overall dimensions of 48 mm x 14 mm is
printed on one side of a substrate of dielectric
constant 4.4 and height 1.6 mm.
Description:
Recent Advances in Microwave Theory and Applications, 2008. MICROWAVE 2008. International Conference on
Deepu, V; Rohith, K R; Manoj, J; Suma,M N; Vasudevan, K; Aanandan,C K; Mohanan, P(Electronics Letters, January 18, 2007)
[+]
[-]
Abstract:
A compact dual-band uniplanar antenna for operation in the 2.4/5.2/5.8 GHz WLAN/HIPERLAN2 communication bands is presented. The dual-band antenna is obtained by modifying one of the lateral strips of a slot line, thereby producing two different current paths. The antenna occupies a very small area of 14.5times16.6 mm2 including the ground plane on a substrate having dielectric constant 4.4 and thickness 1.6 mm at 2.2 GHz. The antenna resonates with two bands from 2.2 to 2.52 GHz and from 5 to 10 GHz with good matching, good radiation characteristics and moderate gain
Binu, Paul; Mridula, S; Mohanan, P; Bijumon, P V; Sebastian,M T(Microwave and Optical Technology Letters, October 20, 2004)
[+]
[-]
Abstract:
very-high-permittivity (e, = 100) multiband dielectrice>
e resonator antenna is presented. The compact antenna, excited by a
m:'crostrip line, resonates at two frequencies centered around the 1.9-
GHz and 2.4-GHz bands with identical polarization . The behavior of the
antenna at different positions along the feed line is studied and optimized.
Multiple resonances with the same polarization and broad radioticn
patterns suggest the suitability of the antenna for multiband wireless
application
Mohanan, P; Joseph,M; Paul,B; Raj,R K(Department of Electronics, November 11, 2004)
[+]
[-]
Abstract:
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band is presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of -5 dBi. The antenna can be excited
directly using a 50 coaxial probe
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band are presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of~5 dBi. The antenna can be excited
directly using a 50 coaxial probe
Bright Singh, I S; Shibu, K Mani; Ranjit, Kanjur; Robert, Reed H(Elsevier, November 23, 2005)
[+]
[-]
Abstract:
This study investigated the enhancement of solar disinfection using custom-made batch
reactors with reflective (foil-backed) or absorptive (black-backed) rear surfaces, under a
range of weather conditions in India. Plate counts of Escherichia coli ATCC11775 were made
under aerobic conditions and under conditions where reactive oxygen species (ROS) were
neutralised, i.e. in growth medium supplemented with 0.05% w/v sodium pyruvate plus
incubation under anaerobic conditions. While the addition of either an absorptive or a
reflective backing enhanced reactor performance under strong sunlight, the reflective
reactor was the only system to show consistent enhancement under low sunlight, where
the process was slowest. Counts performed under ROS-neutralised conditions were slightly
higher than those in air, indicating that a fraction of the cells become sub-lethally injured
during exposure to sunlight to the extent that they were unable to grow aerobically.
However, the influence of this phenomenon on the dynamics of inactivation was relatively
small
There is a growing commercial interest in the ¢sh,
Puntius ¢lamentosus, in the ornamental ¢sh trade in
India and elsewhere.The trade is, however, hampered
by severe mortalities during transport of the ¢sh owing
to insu⁄cient data available on the use of anaesthetics.
To resolve this problem, we evaluated the
e⁄cacy of two anaesthetics, MS-222 and benzocaine,
in sedating P. ¢lamentosus in simulated transportation
experiments and used stress response parameters
such as cortisol and blood glucose levels to
perform assessments. We observed that MS-222 at
40 mg L 1 and benzocaine at 20mg L 1 were su⁄-
cient to induce sedation for 48 h. Above these concentrations,
both the anaesthetics adversely a¡ected
the ¢sh and resulted inmortalities. Both anaesthetics
signi¢cantly lowered the blood cortisol and glucose
levels compared with the unsedated controls. Importantly,
the anaesthetics treatment signi¢cantly lowered
the post-transport mortality in the ¢sh.
The results of the study show that MS-222 and benzocaine
could be used as sedatives to alleviate transport-
related stress in P. ¢lamentosus to improve
their post-transport survival and hence reduce
economic loss.
Jinesh, Mathew; Mahesh, V V; Radhakrishnan, P(International Frequency Sensor Association, August , 2008)
[+]
[-]
Abstract:
The design and fabrication of fiber based ammonia sensors employing Bromothymol blue
and Chitosan as sensing elements are presented in this paper. In the presence of ammonia gas the
absorption of Bromothymol blue changes while in the case of Chitosan the refractive index changes
which in turn modulates the intensity of light propagating through a fiber.