Home – Home – Jornals – Avtometriya 2005 number 1

Theoretical analysis of microbolometer operation at dc bias is carried out. Four basic signal measurement circuits are considered: at fixed current and voltage, and two modifications of a bridge circuit. Relationships for the noise-equivalent power are obtained taking into account the fluctuations of thermal fluxes, Johnson and  noises of the bolometer, and noises of the readout circuit and the power supply. It is shown that the certain part of noise sources, depending on the measurement circuit, causes fluctuations in the power of the Joule heat emission in the bolometer, and this, in turn, results in increasing temperature fluctuations as the bolometer bias increases. The Joule power fluctuations appear to be comparable (or greater) with the thermal flux fluctuations for metal bolometers.