Micromachined Reconfigurable Planar Reflectarray Antenna

In applications such as target tracking the ability to steer the radiation pattern produced by an antenna is required. This can be achieved using reconfigurable reflector antennas based on a planar array of dipole elements immersed in a circularly polarised field. In this paper, we present a new type of reconfigurable planar reflectarray designed for operation with circularly polarised signals. The devices employ a rack and pinion arrangement fabricated using microelectromechanical system (MEMS) technology. A 16 times 16 array of elements has been fabricated with each dipole element located on a rotatable disc and connected to a linear rack in groups of 8 in order to facilitate ID scanning. The structure, designed for 110 GHz operation uses 1360 mum long, 100 mum wide dipole elements located with 2100 mum pitch. This paper concentrates on the main issues related to fabrication of the structure.