Submitted in partial fulfilment of the requirements for the award of Diploma in Electronic and Communication Engineering from Sankar Institute of Polytechnic, Sankarnagar (Tirunelveli) during 1995-1996. Under the guidance of Mr.R. Kalidasa Krishnaswamy and Mr. Jothi from Sankar Institute of Polytechnic & Dr. S. Gurubaran from EGRL, Tirunelveli.