9   Antennas

Martin Smith

Nortel Ltd.

Types of Antenna

Antennas form the link between the guided parts and the free-space parts of a communications system. The purpose of a transmitting antenna is to efficiently transform the currents in a circuit or waveguide into radiated radio or microwave energy. The purpose of a receiving antenna is to efficiently accept the received radiated energy and convert it into guided form for detection and processing by a receiver. The design and construction of an antenna usually involves compromises between the desired electromagnetic performance and the mechanical size, mass, and environmental characteristics.

Antennas for communications systems fall into two broad categories depending on the degree to which ...

Get The Cable and Telecommunications Professionals' Reference, 3rd Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.