Overview of a miniaturized high-gain reflectarray antenna

This paper briefly overviews a new technique to miniaturize a reflectarray antenna (RA). Conventional RAs use a directional feeder distant from a reflectarray, which is generally in a far-field region, to clearly determine the incident phase on the reflectarray. However, we have successfully proven that the feeder can also be in a near-field region to provide relatively high antenna gain by adding a new design constraint; enforcement of constructive interference between a direct wave from the feeder and reflected waves from the reflectarray. Accordingly, we can reduce the overall size of RAs more than 500 times compared to conventional ones in terms of electrical volume. In addition, we also verify that the miniaturized RA with one source feeder can steer its main beam electrical by way of external DC biasing.