Design of a C-band reflectarray element with full phase tuning range using varactor diodes

This paper presents a novel design of a tunable reflectarray element for applications requiring electronic beam scanning capabilities. The element consists of an aperture-coupled microstrip patch and two varactor diodes. The paper presents the principle of operation, the design approach, and the achieved performance of the tunable element. The measured results show a full phase tuning range with maximum losses of 2.7 dB for the element at the center frequency of 5.35 GHz.