High power quasi-optical millimeter-wave beam control array using resonant tunneling devices

At UCLA, multifunction beam control arrays have been fabricated, and have successfully demonstrated amplitude modulation, phase shifting, beam steering (/spl plusmn/6/spl deg/) and beam focusing at frequencies up to 170 GHz. High speed switching arrays capable of generating subnanosecond pulses with octave bandwidths have also been designed. A new lossless millimeter-wave beam controller family based on Schottky diodes and resonant tunneling diodes (RTDs) is described here. Negative differential resistance (NDR) is used to dramatically reduce the loss in beam control applications. Simulations demonstrate that a 300/spl deg/ phase range with virtually no loss can be obtained at 60 GHz with a pair of stacked grids. Lossless wide angle beam steering should be realizable. An improved electronically controlled beam switching array can be obtained with a contrast ratio (on-off radio) of at least 35 dB.<
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