Development of a 3/spl times/3 micromachined millimeter wave SIS imaging array

The design of, and preliminary results from, a 3/spl times/3 micromachined millimeter wave focal plane imaging array with superconducting tunnel junctions as mixing elements are presented. The array operates in the 175-205 GHz frequency range. Micromachined horn antennas consist of a dipole antenna fabricated on a thin dielectric membrane inside a pyramidal cavity etched in silicon. The relative ease of fabricating arrays of micromachined antennas make them of particular interest in the development of imaging arrays. DC tests of the array show that the junction characteristics are uniform across the array. The devices are sufficiently cooled. Local oscillator power has been coupled to the different elements in the array.