Electronically Tunable Beam Scanning Reflectarray using Frequency Selective Surface

An electronically tunable reflectarray (RA) is designed using a frequency selective surface (FSS) in the Ku-Band. The design consists of two layers. At the top layer, multiple smaller sized patches are used as the radiating element while a circular slotted patch is used as an FSS at the bottom layer. The element is a square of length 10mm (0.43λ at 13.1 GHz). A surface mount varactor diode is attached at the top layer geometry. A biasing network is considered to isolate the RF signal from DC. The element provides a maximum phase tuning range of 270° with an amplitude loss under 3 dB. For a proof of concept, a 7 × 7 reconfigurable RA is designed for the center-fed method and its performance is evaluated for H-plane scanning. A stacked patch is used as a feed. The proposed reconfigurable RA provides electronic beam scanning ability within ±30° (@ 13.1 GHz).