Design and measurements of a 1-bit reconfigurable elementary cell for large electronic steerable reflectarrays

This paper presents a reconfigurable MEMS based radiating element for the realization of a large beam-steering reflectarray operating at 77 GHz. The elementary cell consists of a square patch slot-coupled to a phase shifting circuit realized in slot-line technology, with 1-bit phase resolution (0°/180°). Reconfigurability is obtained by integrating MEMS switches in the slot-lines. In order to obtain the best performance in terms of loss, the structure is fully realized on quartz. A board made of 16×16 elementary cells in hardwired configuration has been manufactured and tested with a dedicated measurement setup employing a pair of horns. The experimental results confirm the operating principle of the cell and the design procedure.