An asymmetric coplanar strip (ACS) fed dual band F-shaped antenna covering the 2.4/5.2 GHz WLAN bands is presented. The optimized dimensions of the proposed uniplanar antenna are 21 mm × 19 mm when printed on a substrate of dielectric constant 4.4 and height 1.6 mm. The dual band nature of the antenna is brought about by the various current paths in the F-shaped structure and the ground plane. The antenna exhibits nearly omnidirectional radiation characteristics and moderate gain in both the operating bands. Details of the antenna design, simulation, and experimental results are presented and discussed.
Mridula, S; Mohanan, P; Nijas, C M; Dinesh, R; Abdul, Rasheed; Vasudevan, K(IEEE, August 30, 2012)
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Abstract:
A novel compact RFID tag employing open stubs in a
microstrip transmission line is proposed. The prototype of the tag is
fabricated on a substrate of dielectric constant 4.4 and loss tangent 0.0018.
The tag consists of microstrip open stub resonators and cross polarized
transmitting and receiving disc monopole antennas. A prototype of 8 bit
data encoded tag is demonstrated in this communication. Method for
enhancing the performance of the RFID tag is also proposed. Magnitude
or group delay response can be used to decode the tag informations
Description:
Antennas and Propagation, IEEE Transactions on,VOL 60,issue 9,pp 4428-4432
Design of a dual-port circular patch antenna with a sector-slot for dual-frequency operation is presented. The antenna resonates at two distinct frequencies with orthogonal polarizations and broad radiation characteristics. Unlike the conventional circular patch, this antenna can be microstrip-fed to operate at either of the resonances. The two polarizations can be simultaneously excited using two electromagnetically coupled ports with an isolation better than −30 dB between the ports. This antenna has the added advantage of size reduction of 44% compared to the conventional circular patch without any reduction in gain.
Rohith, Raj K; Sona,Kundukulam O; Aanandan,C K; Vasudevan, K; Mohanan, P; Praveen,Kumar(Microwave and Optical Technology Letters, February 20, 2004)
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Abstract:
compact microstrip antenna integrated with an amplifier
having an area reduction of 70%, compared to the standard circular microstrip
patch antenna, is presented. The antenna also provides an enhanced
gain of 10-dB more than its passive counter part. The measured 2:1
VSWR band width is -4% at 790 MHz, which is 2.5 times larger than that
of the passive microstrip antenna
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
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)
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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)
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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)
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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)
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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
Thomas, Paulbert; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Wiley InterScience, October , 2010)
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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.
Deepu, V; Rohith, K R; Manoj, J; Suma,M N; Vasudevan, K; Aanandan,C K; Mohanan, P(Electronics Letters, January 18, 2007)
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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
Shynu, S V; Augustin, G; Aanandan,C K; Mohanan, P; Vasudevan, K(IET, March 16, 2006)
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Abstract:
A new electronically reconfigurable dual frequency microstrip patch antenna with highly simplified varactor tuning circuitry is presented. The proposed design allows relatively independent selection of the two operating frequencies. Tuning ranges of 7.1 and 4.1% are realised for the two resonant frequencies without the use of any matching circuits.
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
Zachariah,E J; Vasudevan, K; Pravinkumar,P A; Mohanan, P; K G Nair(Indian Journal of Radio & Space Physics, February , 1984)
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Abstract:
The design, erection and evalution procedures for it microwave anechuic chamber competed at Cochin University for
antenna studies are presented the chamber has an average reflectivity level of - 32 dB on at X-band frequencies, and it i,
comparable to international standards.