Broadband single-layer triple-resonance microstrip reflectarray antennas

This paper presents single-layer microstrip reflec-tarray antennas based on triple-resonance behavior and also discusses their broadband characteristics. The reflection phase properties can be evaluated by using infinite arrays of a rectangular cell consisting of three elements with different dimensions. Appropriate three elements for obtaining arbitrary phase value are determined by taking account of both range of the phase shift at the centre frequency and its slope for the frequency characteristics. We design various reflectarrays with a main beam in a specified direction and also evaluate the frequency characteristics. Finally, the effectiveness of the designed antenna is verified by calculated and measured results around 10–19 GHz.