Measured characteristics of a planar array of parasitic elements fed by one active element

Abstract

An antenna design based on the use of an active dipole placed above a ground plane with an array of parasitic dipoles is presented. The presence of the parasitic dipoles increases the effective antenna size and significantly improves directivity over that of an isolated dipole in front of a ground plane. In addition, the use of just one active element makes for a very simple feed network that reduces the complexity of the antenna. As an application of this technique, a planar array of 48 parasitic dipoles above a ground plane, fed by a single active dipole at 5 GHz, was designed to afford a pencil beam pattern of moderate gain and bandwidth. Measurements agree well with theory. With a protective radome in place, directivity and gain were, respectively, 15.30 and 14.78 dB, the sidelobe level −6.15 dB, and the bandwidth 12.7% for S11 < −10 dB and 3.1% for gain loss <3 dB. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2807–2809, 2015