An optically transparent end-fire magnetoelectric dipole antenna array for millimeter-wave applications

A simple, planar, low-profile and wideband optical transparent end-fire magnetoelectric (ME) dipole antenna array is presented in this article. The metal mesh printing on the glass substrate uses a conductive silver grid layer. The top layer has electric and magnetic dipoles with the coplanar ground. An Gamma-shaped transmission line is used to feed the ME dipole antenna and printed on the bottom layer. Good radiation performance of single antenna element, including an impedance bandwidth of 24.9%, average gain of 8 dBi, radiation efficiency of over 80%, and end-fire radiation patterns at 28 GHz band, are also achieved. Furthermore, a 1 x 4 transparent end-fire ME-dipole antenna array is realized by employing the proposed ME-dipole single antenna element. A prototype was fabricated by in-house photolithography and lift-off process, which is measured to confirm the simulation results. Measured impedance bandwidth is 33% from 23.3 to 32.5 GHz (VSWR <= 2). End-fire radiation patterns are obtained across the entire bandwidth with a peak gain and radiation efficiency of 13.6 dBi and 80%, respectively. The optical transparency is around 66% across the visible spectrum.