Gopakumar,C; Dr.Mathew, K T(Cochin University of Science and Technology, January , 2011)
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Abstract:
This thesis describes the development and analysis of an Isosceles Trapezoidal
Dielectric Resonator Antenna (ITDRA) by realizing different DR orientations with
suitable feed configurations enabling it to be used as multiband, dual band dual
polarized and wideband applications.
The motivation for this work has been inspired by the need for compact, high
efficient, low cost antenna suitable for multi band application, dual band dual polarized
operation and broadband operation with the possibility of using with MICs, and to
ensure less expensive, more efficient and quality wireless communication systems. To
satisfy these challenging demands a novel shaped Dielectric Resonator (DR) is
fabricated and investigated for the possibility of above required properties by trying out
different orientations of the DR on a simple microstrip feed and with slotted ground
plane as well.
The thesis initially discusses and evaluates recent and past developments taken
place within the microwave industry on this topic through a concise review of
literature. Then the theoretical aspects of DRA and different feeding techniques are
described. Following this, fabrication and characterization of DRA is explained.
To achieve the desired requirements as above both simulations and
experimental measurements were undertaken. A 3-D finite element method (FEM)
electromagnetic simulation tool, HFSSTM by Agilent, is used to determine the optimum
geometry of the dielectric resonator. It was found to be useful in producing
approximate results although it had some limitations. A numerical analysis technique,
finite difference time domain (FDTD) is used for validating the results of wide band
design at the end. MATLAB is used for modeling the ITDR and implementing FDTD
analysis.
In conclusion this work offers a new, efficient and relatively simple alternative
for antennas to be used for multiple requirements in the wireless communication
system.
Description:
Department of Electronics, Cochin
University of Science and Technology
Shahana, T K; Dr.Poulose Jacob, K; Dr.Sreela, Sasi(Cochin University of Science and Technology, October , 2008)
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Abstract:
The thesis focuses on efficient design methods and reconfiguration architectures suitable for higher performance wireless communication .The work presented in this thesis describes the development of compact,inexpensive and low power communication devices that are robust,testable and capable of handling multiple communication standards.A new multistandard Decimation Filter Design Toolbox is developed in MATLAB GUIDE environment.RNS based dual-mode decimation filters reconfigurable for WCDMA/WiMAX and WCDMA/WLANa standards are designed and implemented.It offers high speed operation with lesser area requirement and lower dynamic power dissipation.A novel sigma-delta based direct analog-to-residue converter that reduces the complexity of RNS conversion circuitry is presented.The performance of an OFDM communication system with a new RRNS-convolutional concatenated coding is analysed and improved BER performance is obtained under different channel conditions. Easily testable MAC units for filters are presented using Reed-Muller logic for realization.
Description:
Department of Computer Science,
Cochin University of Science and Technology