Saira Joseph; Dr. Binu Paul(Cochin University of Science and Technology, November 20, 2016)
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Abstract:
Over the past decade, there is a great demand for permission to transmit large bandwidth
concurrent with existing narrowband signals. In 2002, the federal communications
commission (FCC) decided to permit use of ultrawideband (UWB) systems.
UWB systems are unique in their large instantaneous bandwidth and potential for lowcost
digital design that enables a single system to operate in different modes as a
communication device, radar etc. UWB systems aim at covering the frequency band of
3.1-10.6 GHz defined by the FCC. The addition of more and more features in each new
generation communication system demands universal antennas suitable for operation in
multiple bands. In this regard, designing a multiband antenna which also covers the
UWB range without deteriorating the UWB performance is of great interest. Also, a
significant issue in communication systems is to miniaturize the antenna size while
providing good performance over the operation bands.
The thesis presents three different designs of CPW-fed multiband antennas. The first
design uses a fractal concept to achieve multiband operation. In the second and third
designs, a slotted circular monopole and a spiral monopole are used respectively for
multiband operation with UWB applications. For both these cases, variations from the
basic antenna geometry are also proposed in which the frequency of operation is
lowered without increase in overall antenna size. Design guidelines are developed for
all antennas to facilitate design on substrates of different permittivity and thickness. The
antennas are analyzed in both frequency and time domain for complete characterization
Sona,Kundukulam O; Dr.Aanandan, C K(Cochin University of Science and Technology, June , 2002)
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Abstract:
The practical applications of microstrip antennas for mobile systems are in
portable or pocket-size equipment and in vehicles. Antennas for VHFIUHF handheld
portable equipment, such as pagers, portable telephones and transceivers,
must naturally be small in size, light in weight and compact in structure. There is
a growing tendency for portable equipment to be made smaller and smaller as the
demand for personal communication rapidly increases, and the development of
very compact hand-held units has become urgent.In this thesis work, main aim is to develop a more and more reduced sized
microstrip patch antenna. It is well known that the smaller the antenna size, the
lower the antenna efficiency. During the period of work, three different compact
circular sided microstrip patches are developed and analysed, which have a
significant size reduction compared to standard circular disk antenna (the most
compact one of the basic microstrip patch configurations), without much
deterioration of its properties like gain, bandwidth and efficiency. In addition to
this the interesting results, dual port operation and circular polarization are also
observed for some typical designs of these patches. These make the patches
suitable for satellite and mobile communication systems.The theoretical investigations are carried out on these compact patches. The
empirical relations are developed by modifying the standard equations of
rectangular and circular disk microstrip patches, which helps to predict the
resonant frequencies easily.
Description:
Department of
Electronics, Cochin University of Science and Technology