Millimeter-wave imaging array development for microwave reflectometry and ECE imaging

Millimeter-wave imaging arrays employing slot bow-tie (SBT) antenna element s and GaAs Schottky diodes have previously been previously successfully dev eloped and utilized in electron cyclotron emission imaging systems, which h ave proven to be an important new plasma diagnostic technique for measuring plasma electron temperature profiles and fluctuations. More recently, ther e has been interest in applying similar arrays for reflectrometric imaging. Here, the design of SBT antennas for proof-of-principle millimeter-wave im aging reflectometry receiver arrays for use on Torus Experiment for Technol ogy Oriented Research is presented. These low-cost, 14-channel Schottky mix er diode arrays, designed at 85 GHz, have been developed for measuring plas ma electron density fluctuation profiles, which are expected to solve the l ong standing issue of ambiguity in the interpretation of reflectometric dat a. The final layout of the array is shown, together with details and experi mental results of single SBT antennas. (C) 2001 American Institute of Physi cs.