INVESTIGATIONS ON CERIA BASED DIELECTRIC CERAMIC MATERIALS FOR WIRELESS COMMUNICATION THESIS SUBMITTED TO COCHIN UNIVERISTY OF SCIENCE AND TECHNOLOGY IN PARTIAL FULFILMENT OF REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN PHYSICS P. S. ANJANA Under the guidance and supervision of Dr. M. T. SEBASTIAN I) NATIONAL INSTITUTE FOR INTERDISCIPLINARY SCIENCE AND TECHNOLOGY (CSIR), THIRUVANANTHAPURAM NOVEMBER 2008