Dual-band Ka/X reflectarray with broadband loop elements

The objective of this paper is to carry out analysis and design for X/Ka dual-band, frequency selective surface (FSS)-backed reflectarrays. In this design, a novel ring structure has been developed as the cell element for both the X- and Ka-bands to achieve dual-band performance. A single loop was used for the construction of the FSS-backed reflectarray in the Ka-band and a reflectarray with a solid ground plane was designed for the other band. Prototypes of these reflectarrays were fabricated and tested. The measurements demonstrated that for an optimum design, the gain of the FSS-backed reflectarray is almost the same as its counterpart backed by a solid ground plane. Characterisation of the out-of-band performance of these antennas demonstrated a close to 0.6-dB insertion loss.