9360458 Robertazzi SIS heterodyne receivers integrated with on-chip local oscillators for use in radio astronomy will be developed. The receivers will incorporate superconducting tunnel junctions (SIS junctions) as the mixing elements together with Josephson junction local oscillators to provide mixing in the 50-700 GHz frequency band. Local oscillators based on the ac Josephson effect have demonstrated operation up to frequencies in excess of the superconducting tunnel junction gap frequency, about 1.5 THz for Nb and 3 THz for NbN. These oscillators may be tuned electrically, are extremely compact and dissipate small amounts of power. Recently, Josephson junction array oscillators have been fabricated from which more than 125 nW has been coupled into a 10 ohm load at 105 GHz. The oscillators will be used to produce monolithic millimeter/submillimeter wave heterodyne receivers. These receivers have intrinsic utility for radio astronomy, and would have application in advanced communication and radar systems as well. ***
