Dielectric Loaded and Covered Rectangular Waveguide Phased Arrays

The advent of swift aircraft, missile warfare, and the need for modem radar to accomplish multifunction detection has given impetus for a considerable amount of research into phased-array antennas. Such arrays consist of a large group of small radiators in a grid, frequently a rectangular grid, and, most important, correlated in phase and amplitude. The radiated beam can be steered by an electronicallyvariable linear taper of the phase correlation among elements. (See Fig. 1). Considerable knowledge of the behavior and problems of such arrays has been obtained in recent years by experimental and theoretical study of phased linear and parallel plate arrays. For example, it is well known that the coupling coefficients between any single excited element in the array and any terminated inactive element is uniquely determined by the inverse Fourier series transform of the reflection coefficient as a function of scan angle determined when all elements are excited.1 Hence, by studying the array behavior for all possible linear tapers of phase, we can determine the behavior of the array, for any phase or amplitude distribution among the elements. 93