Design and implementation of multiband and broadband microstrip antennas for wireless systems

Abstract

With advancement in wireless systems, the device size is shrinking. The modern day wireless systems are termed as next generation wireless systems. The modern day, small size wireless devices are not just limited to voice conversation but also support high data rate multimedia applications like VoIP, video conferencing, wireless broadband and online gaming etc. The high data rate can be achieved by increasing the bandwidth support of the system. Antenna being important integral part of wireless system requires to support broad bandwidth. The heterogeneous technology support to wireless system is other advancement in next generation wireless systems. So the antenna for next generation wireless devices require support to larger bandwidth and support to multiple technology. This motivation leads to research presented in the thesis. The thesis is organized with four objectives. The first objective is devoted to the study of different type of techniques for multiband and broadband operation. In process for achievement of first objective, the historical development in wireless systems are considered for insight to different technology and application support. The planar antenna has advantages of being conformal, low profile, small size and ease of integration with device PCB. So the challenge is to design multiband and broadband planar antennas. The length of antenna is frequency dependent so specific techniques can achieve multiband and broadband operation. In this thesis, the different techniques which are already presented in literature for achieving multiband and broadband support to microstrip antennas are surveyed. In the next chapters, the different designs to achieve multiband operation are discussed. This is second objective of the thesis. The planar multiband antenna is designed and termed as multiband microstrip patch antennas. To start with, the planar antennas with different type of feeds are compared. The slot in patch of MPA is one method to achieve multiband operation of planar antenna.