Ultra Wide Band Antennas

Chapter 4

Experimental Characterization of UWB Antennas ¹

4.1. Introduction

Experimental characterization is an essential stage in the design of antennas. Precise measurements of the characteristics of aerials are necessary for many applications using antennas with well established properties.

In many cases, the properties of the antennas can be calculated theoretically. However, for the complex structures of antennas, these calculations are not always possible. Estimates of properties can be advanced by the means of increasingly powerful electromagnetic simulations, but are often carried out with certain simplifications of the structures and by making assumptions on the properties of materials. This is particularly the case for compact antennas integrated in their operational environment. Thus, measurement always appears essential to the characterization of the real performances of the antennas. Indeed, the processes and materials used for their manufacture generally introduce factors of dispersion which are not taken into account in a more or less ideal modeling. However, if measurements are often taken as values of reference performance, they are also prone to errors which it is then advisable to quantify.

The experimental characterization of antennas generally aims at measuring the parameters describing the conventional performances of the antennas: the radiation pattern, polarization, directivity, gain, efficiency and impedance. These measurements are usually taken at discrete ...