Theory of gated multicycle integration (GMCI) for repetitive imaging of focal plane array

Gated multicycle integration (GMCI), a model of a directly gated readout circuit, is developed for repetitive imaging focal plane arrays (FPAs). The concept of GMCI is a combiner of gated integration (GI) and phase-sensitive integration (PSI). It differs from GI by its capability of background subtraction, and it differs from phase-sensitive integration by its duty cycle unlimited to 0.5. The operational modes of GMCI include the capacitive transimpedance amplifier (CTIA), GI, PSI (with background subtraction), multiple summation, multiple averaging, and some of their combinations. Through discussing the performance of one pixel, the analytical theory of GMCI provides the background limitations of gated and nongated FPAs.