. (1990) Standards, standardizing, standardization, TE&M, Sahin, V., Omidyar, C.G. and Bauman, T.M. (1988) Telecommuni- May 1. cations Management Network (TMN) architecture and inter- Joseph, C.A. and Muralidhar, K.H. (1990) Integrated Network Man- working designs, IEEE Journal on Selected Areas in agement in an enterprise environment, IEEE Network Maga- Communications, May. zine, July. Trew, D. (1991), Network management: coming of age? Telecom- munications, February. Klerer, S.M. (1988) The OSI management architecture: an over- Warrier, U.S. and Sunshine, C.A. (1990) A platform for heteroge- view, IEEE Network Magazine, March. neous interconnection network management, IEEE Journal on Mazda, F.F. (1991) Convergence or collision: SNMP and CMIP, Selected Areas in Communications, January. Telecommunications, Part 1: September; Part 2, November. Yoshida, M., Kobayashi, M. and Yamaguchi, H. (1990) Customer Mazda, F.F. (1991) Structured network management, Communica- control of network management from the service provider's tions International, December. perspective, IEEE Communications Magazine, March. This page intentionally left blank Antennas Professor A D Olver BSc PhD CEng FIEE FIEEE Queen Mary and Westfield College Contents 17.1 Types of antennas 17/3 17.2 Basic properties 17/4 17.3 Generic antenna types 17/5 17.4 Specific antenna types 17/8 17.5 Antennas used in communication systems 17/12 17.6 References 17/17 This page intentionally left blank Types of antennas 17/3 Types of antennas Antennas form the link between the guided parts and the free-space parts of a communication system. The purpose of a transmitting antenna is to efficiently transform the currents in a circuit or wave- guide into radiated radio or microwave energy. The purpose of a receiving antenna is to efficiently accept the received radiated energy and convert it to guided form for detection and processing by a receiver. The design and construction of an antenna usually involves compromises between the desired electromagnetic perfor- mance an