TABLE OF CONTENTS The antenna is the connecting link between free-space and the transmitter or receiver. As such, it plays an essential part in determining the characteristics of the system in which it is used.
Henry Jasik, 1961
Thus far, this book has considered UWB antennas as an individual component characterized by certain properties and parameters. UWB antennas do not exist in a vacuum, however. They are part of an overall RF system designed to meet the requirements of specific applications. A UWB antenna may work together with other components of a system to meet overall system goals. A poorly designed antenna will detract from overall system performance. The aim of this chapter is to explore how antenna-system interactions can improve system performance.
The shortcomings and deficiencies of a traditional narrowband antenna operating at a particular frequency may often be accommodated by an easily designed matching filter. A poorly matched UWB antenna may benefit somewhat from a matching network, but a better approach is to design in a good match from first principles. Chapter 3 addresses this important topic. While a good impedance match is crucial, an important corollary is "over what frequencies?" This chapter addresses additional techniques for spectral control using UWB antennas, including use of UWB antennas to provide spectral filtering.
Antenna efficiency is also an important system-level concern. Inefficient antenna operation impacts system performance and cannot easily be remedied elsewhere in the system. Thus, this chapter will discuss UWB antenna efficiency and present a technique for assessing UWB antenna...
