TABLE OF CONTENTS Of the many different kinds of elements used in array systems, most can be considered either as wire antennas, or slots, or a combination of these. Most arrays are designed with conducting ground screens, and so the potential functions introduced in Chapter 2 can be used to evaluate near-field coupling effects as well as far-field radiation. Many arrays have been built using printed circuit dipoles or microstrip patch antennas, and the use of dielectric substrates above the metallic ground screen requires a more complex analytical formulation than that of Chapter 2. Similarly, arrays built of dielectric rods or other dielectric elements require a more generalized formulation.
The intent of this chapter is to catalog a body of technology that constitutes the hardware of phased arrays. Since the chapter deals with isolated elements, and the behavior of these elements is not directly relevant to their behavior in the array, the chapter presents only simple approximate equations for element impedance and radiation patterns. Many of the equations are for the resonant cases, even though there exists a vast body of technical literature for isolated elements of various resonant and nonresonant dimensions. Resonant data are given here to address the engineering problem of matching element impedance to the feed transmission line. The detailed evaluation of element behavior in a scanned array and the element patterns in an array environment will be discussed for some of these elements in Chapter 6.
The...
