ABSTRACT
In this chapter some general concepts associated with antennas are introduced. These concepts are valid for both narrowband and non-narrowband antennas. It is not the objective of this book, however, to present a detailed theory in the field of antennas. A wide variety of excellent references for theory and practice on classical narrowband and broadband antennas can be found in the open literature [1-5]. The particularities of the case of UWB antennas will be addressed in Chapter 4. In order to provide some fundamentals on these devices, the most representative classical narrowband antennas are briefly presented below.
