*** 9501307 Robertazzi This Small Business Innovation Research Phase II project will develop a 100 GHz integrated receiver for millimeter wave heterodyne detection. Millimeter wave receivers have direct application in radio astronomy, and may be used to construct multipixel mm wave imaging arrays. The receivers which will be developed in Phase II will use SIS junctions as the nonlinear mixing elements in combination with on chip local oscillators based on the ac Josephson effect. The advantages of such an arrangement include (i) complete integration of all the elements required to produce a heterodyne receiver in a single compact circuit, (ii) extremely low power dissipation of the local oscillator, (iii) the ability to tune the local oscillator electrically, making the system frequency agile, (iv) the possibility of attaining the quantum detection limit at mm wavelengths, and (v) easy fabrication of large mixer arrays for mm wave imaging applications. The research objectives include the development of a 100 GHz receiver design which can be extended to higher operating frequencies (500 Ghz). It is anticipated that the noise temperature of the receivers will be better than 10 times the quantum limit. Support under the NSF SBIR program will establish a commercial source of monolithic SIS quasi-optical receivers. These elements are in demand for radio astronomy, as well as advanced radar and secure communications systems. They will find application in advanced far infrared spectrometers and mm wave imaging systems. A mm wave camera can be used to make images showing the presence in small amounts of all possible atmospheric pollutants. These capabilities have great commercial utility in both civilian and military applications. ***
