Dynamic Beam Shaping Using a Dual-Band Electronically Tunable Reflectarray Antenna

An electronically reconfigurable dual-band reflectarray antenna is presented in this paper. The tunable unit cell, a ring loaded square patch with a single varactor diode connected across the gap between the ring and the patch, is modeled using both a full-wave solver and an equivalent circuit. The parameters of the equivalent circuit are calculated independently of the simulation and experiment using analysis techniques employed in frequency-selective surfaces (FSSs). The reflection phase of the proposed unit cell is shown to provide an excellent phase range of 335° in F-band and 340° in S -band. Results from the analysis are used to design and build a 10 × 10 element reflectarray antenna. The high tuning phase range of each element allows the fabricated reflectarray to demonstrate a very broad steering range of up to ± 60° in both frequency bands.