An All-Metal Folded Reflectarray Adopting Mushroom-Shaped Slot Elements

An all-metal folded reflectarray with mushroom-shaped slot elements is proposed. The element is able to realize a linear 360° phase swing by adjusting the slot length and also mirroring its configuration. The folded reflectarray is composed of a bottom reflectarray embedded with a feed and a top polarizer. The electromagnetic waves from the feed are reflected twice between the reflectarray and the polarizer so that the antenna profile is reduced to half of the traditional reflectarray. Simulations reveal that the all-metal folded reflectarray has 1-dB gain bandwidth of 14% with maximum aperture efficiency of 42%.