Analysis of 320X240 uncooled microbolometer focal plane array ...

19F is the f/# of the optics, VN is the electrical noise within the system bandwidth, T o is thetransmittance of the optics and (AP / AT),I _ 12 is the rate of change of the radiated powerper unit area of a blackbody at temperature T s measured within the spectral interval from2 to k2. The relationship between D* and responsivity R is defined asD*(A DV B) 12 2 R (2.34)Nwhere B is the measurement bandwidth.Substituting Equation 2.30 to Equation 2.33 and with Equation 2.34, theexpression for the noise equivalent temperature difference in a temperature fluctuationFigure 2.6 a) and b), respectively, illustrates Equations 2.35 and 2.36, where allthermal infrared detectors must fall on or above the limits shown. With a given value ofG, a detector cannot have an NETD better than or points lower than the sloping line. Theactual detectors usually lie above the sloping line due to higher noise than that oftemperature fluctuation noise. Within the parameters given, no detector can have NETDbetter than (lower than) the background limit shown.