ABSTRACT
An antenna is a structure that serves as an interface between any transmission line and free space whose purpose is to radiate or receive electromagnetic waves. The transmission line can be anything such as a simple wire, coaxial cable, or waveguide. As long as the transmission line can efficiently transfer electromagnetic energy to and from the antenna, the antenna can operate as the transitional device. Thus, an antenna can act as a receiver for incoming energy from an electromagnetic field or as a radiator of electromagnetic waves. This chapter presents different types of antennas and antenna array in 1-D, 2-D and 3-D configurations commonly used in Radar systems. Different methods for tapering the antenna radiation characteristics are illustrated through expressions and numerical examples. Feeding networks (transmission lines) and beam forming networks are also addressed in order to improve the radiation efficiency of these antenna.
