MEMS Electronically Steerable Antennas for Fire Control Radars

Large apertures are of great benefit to applications that are prime powered limited as is found on aerostat and other airborne platforms. Electronically scanned array antennas are often proposed for these applications. However, increasing the aperture area with conventional array technology is met with prohibitive cost, weight, and prime power increases because of the dense spacing of phase shifters and/or active T/R modules. This paper discusses the recent development of RF MEMS (microelectromechanical system) switch technology and the use of these switches in a Radant lens configuration for arrays of approximately 10m² at X-band. A proof-of-concept 0.4m² MEMS electronically steerable antenna (ESA) containing 25,000 MEMS switches has been successfully designed fabricated and tested. The 0.4m² MEMS ESA was then integrated with an AN/APG-67 radar system to form the MEMS demonstration radar system. The MEMS Demonstration Radar system successfully detected both airborne and ground moving targets during a series of extensive radar demonstrations. This is believed to be the first large scale employment of MEMS switches in a scanning antenna and radar system. The low-cost, lightweight and low power technology demonstrated here can enable weight and power constrained platforms with electronic steering.