Real-time millimeter wave image converter

An electronically scanned image dissecting panel has been used for the first time to produce real-time millimeter wave image conversion at 94 GHz. Reflected energy from illuminated targets at 1 to 3 meters range was optically imaged on the face of a 20 × 20 array of large p-i-n diodes mounted in a panel. The diodes were fabricated from high resistivity silicon and measured .5 cm wide by .05 cm thick between contacts by .376 cm deep in the direction of rf transmission. Image dissection was achieved by switching the diodes between high and low conductivity states permitting rf transmission to a single crystal detector placed 10" to 20" behind the panel. A TV like display of the millimeter wave image was generated by applying the detected signal to the Z axis of a CRT. Frame rates up to 35 frames per second were obtained.