Infrared Detector Arrays

23 .2 IMAGING DETECTORS
f f r a m e display frame rate
f k n e e frequency at which the 1 / f noise intersects the broadband noise
f s spatial frequency (cycles/ radian)
g m , L O A D gate transconductance of the load FET in the gate modulated input
circuit
g m gate transconductance of a Field Ef fect Transistor
h Planck’s constant
I D FET drain current
I d e t detector current
I p h o t o detector photocurrent
k Boltzmann constant
K a m p amplifier FET noise spectral density at 1 Hz
K d e t detector noise spectral density at 1 Hz
K F E T FET noise spectral density at 1 Hz
L length-to-width ratio of a bar chart (always set to 7)
MRT minimum resolvable temperature (K)
MTF modulation transfer function for the optics , detector , readout , the
integration process , or the composite sensor
n detector junction ideality or dif fusion constant
N amp , 1/f number of noise carriers for one integration time due to amplifier FET
1 / f noise
N amp , white number of noise carriers for one integration time due to amplifier FET
white noise
N c number of photo-generated carriers integrated for one integration time
n d e t detector junction ideality or dif fusion constant
NE T noise equivalent temperature dif ference (K)
n F E T subthreshold FET ideality
N F P A composite (total) FPA noise in carriers
N kTC , channel CTIA broadband channel noise in carriers
N load , white number of noise carriers for one integration time due to CTIA load FET
white noise
N o s display overscan ratio
N P H O T O N shot noise of photon background in carriers
NSD noise spectral density of a detector or field ef fect transistor ; the 1 / f noise
is often specified by the NSD at a frequency of 1 Hz
N s f source follower noise
N s s serial scan ratio
q electron charge in coulombs
Q B photon flux density (photons/ cm 2 -s) incident on a focal plane array
Q D charge detected in a focal plane array for one integration time