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Planar antenna arrays have been developed at 140 GHz using twin-dipole elements. The initial systems have been fabricated using a hybrid approach with beam lead Schottky GaAs diodes mounted on quartz substrates. Heterodyne measurements of subelement sensitivities have yielded DSB noise temperatures of 12,000 K. Subsequently implementation of completely monolithic systems has been demonstrated using SIS technology.
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Fetterman et al. (1983) studied this question.
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