ANALYSIS OF A HIGH-T-C HOT-ELECTRON SUPERCONDUCTING MIXER FOR TERAHERTZ APPLICATIONS

The prospects of a YBa2Cu3O7-delta hot-electron bolometer mixer for a THz heterodyne receiver are discussed. The modeled device is a submicr on bridge made from a 10-nm-thick film on a high thermal conductance s ubstrate. The mixer performance expected for this device is analyzed i n the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of phonon di ffusion from the film through the substrate and from the him to the no rmal metal contacts is evaluated. The intrinsic conversion efficiency and the noise temperature have been calculated as functions of the dev ice size, local oscillator (LO) power, and ambient temperature. Assumi ng thermal fluctuations and Johnson noise to be the main sources of no ise, a minimum single sideband mixer noise temperature of congruent to 2000 K is predicted. For our modeled device the intrinsic conversion loss at an intermediate frequency of 2.5 GHz is less than 10 dB and th e required LO power is similar to 1-10 mu W. (C) 1997 American Institu te of Physics.