Wideband PAA Technology for MIR

Advanced millimeter-wave imaging technology is under investigation at UC Davis in support of Microwave Imaging Reflectometry (MIR). Foremost of these new technologies is a beam shaping phased antenna array (PAA) system for use in MIR on shaped plasmas such as NSTX. Using microelectromechanical systems (MEMS) delay lines, a true time delay controlled PAA is being developed as an artificial lens with voltage-controllable focal length for launching the illumination beam. Control of the ``lens'' permits the curvature of the illumination beam to be matched to that of the target plasma over a wide range of frequencies. An NSTX design will be presented along with preliminary testing results.