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

Millimeter-wave imaging arrays employing slot bow-tie (SBT) antenna elements and GaAs Schottky diodes have previously been previously successfully developed and utilized in electron cyclotron emission imaging systems, which have proven to be an important new plasma diagnostic technique for measuring plasma electron temperature profiles and fluctuations. More recently, there has been interest in applying similar arrays for reflectrometric imaging. Here, the design of SBT antennas for proof-of-principle millimeter-wave imaging reflectometry receiver arrays for use on Torus Experiment for Technology Oriented Research is presented. These low-cost, 14-channel Schottky mixer diode arrays, designed at 85 GHz, have been developed for measuring plasma electron density fluctuation profiles, which are expected to solve the long standing issue of ambiguity in the interpretation of reflectometric data. The final layout of the array is shown, together with details and experimental results of single SBT antennas. (C) 2001 American Institute of Physics.