TABLE OF CONTENTS The goal of this chapter was to survey the UWB antenna kingdom. This UWB antenna taxonomy looked at five important classes of UWB antennas. Frequency-independent antennas tend to be dispersive and ill suited for many UWB applications. Small-element electric antennas are the workhorse of UWB consumer-electronic applications, combining compact size with omnidirectional field of view. Small-element magnetic antennas are excellent choices for embedded applications, but many of the more common designs have difficulty achieving an omnidirectional field of view. If "small" elements are not small enough, there are a variety of techniques to miniaturize antennas further, including dielectric loading, using device enclosures as radiating elements, and superimposing electric and magnetic small-element antennas.
Larger antennas are required where applications call for higher gain and narrower field of view. Horn antennas are tapered transmission lines that radiate and receive energy in particular directions. Relatively compact planar horn antenna designs are also possible. Reflector antennas are also a possibility when high gain and a narrow field of view are desired.
This completes the taxonomy of UWB antennas. Chapter 7 will move beyond antennas as discrete components to consider how antennas work as part of a more comprehensive system to meet overall system goals.
