Integrated MEMS reflectarray elements

Reflectarrays have attracted substantial interest in recent years as low-profile replacements for reflector antennas, particularly in space applications. Tun-ability adds a new dimension to reflectarrays, en-abling them to form dynamically-controllable radia-tion patterns for beam-forming applications. While various approaches for tuning reflectarray elements have been proposed, successfully demonstrated ap-proaches based on varactor tuning diodes still suffer from loss and linearity issues. Reflectarray elements based on micro-electro-mechanical systems (MEMS) components possess significant potential in address-ing these shortcomings. This paper presents the de-sign of an electronically tunable reflectarray element based on MEMS capacitors. The design and mea-surements of an experimental MEMS reflectarray el-ement are discussed in detail. Key words: reflectarray antenna; micro-electro-mechanical devices; MEMS; varactor; microstrip an-tenna. 1