Deepti Das, Krishna; Dr.Aanandan, C K(Cochin University of Science and Technology, September , 2010)
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Abstract:
In recent years, there is a visible trend for products/services which demand
seamless integration of cellular networks, WLANs and WPANs. This is a
strong indication for the inclusion of high speed short range wireless technology
in future applications. In this context UWB radio has a significant role
to play as an extension/complement to existing cellular/access technology.
In the present work, we have investigated two major types of wide band
planar antennas: Monopole and Slot. Four novel compact broadband antennas,
suitable for poratble applications, are designed and characterized, namely
1. Elliptical monopole
2. Inverted cone monopole
3. Koch fractal slot
4. Wide band slot
The performance of these designs have been studied using standard simulation
tools used in industry/academia and they have been experimentally verified.
Antenna design guidelines are also deduced by accounting the resonances in
each structure.
In addition to having compact sized, high efficiency and broad bandwidth
antennas, one of the major criterion in the design of impulse-UWB systems
have been the transmission of narrow band pulses with minimum distortion.
The key challenge is not only to design a broad band antenna with constant
and stable gain but to maintain a flat group delay or linear phase response
in the frequency domain or excellent transient response in time domain. One
of the major contributions of the thesis lies in the analysis of the frequency
and time-domain response of the designed UWB antennas to confirm their
suitability for portable pulsed-UWB systems. Techniques to avoid narrowband
interference by engraving narrow slot resonators on the antenna is also
proposed and their effect on a nano-second pulse have been investigated.
Description:
Department of Electronics,
Faculty of Technology,
Cochin University of Science and Technology