Properties of coaxial Yagi loop arrays

The resonant properties of circular loops as elements of a coaxial loop array are studied. It is shown that array characteristics can be obtained accurately by retaining only the resonant modes or the few modes around them. Effects of the various array parameters on the array characteristics are also studied. It is found that the reflector, the exciter, and the wire cross section have a small effect on the forward gain and radiation patterns, but the directors have a large effect. All parameters are found to have a large effect on the backward gain and the input admittance.