Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime

Abstract

In this paper, a one-dimensional heat balance model for the hot-spot length of phonon-cooled hot-electron bolometer is set up and solved for the electron temperature profile along the bolometer bridge. A self-consistent theoretical method is presented to obtain the hot-spot length profile as a function of RF and bias heating power. This result is used to predict current-voltage characteristics. For a known hot-spot length profile, a small-signal model with different heating efficiencies for RP and bias heating is derived in the vicinity of an operating point. This small-signal model allows the conversion gain and fluctuation noise contribution to be calculated.