Cyclostationary mode of pyroelectric sensor

Periodically variable pyroelectric systems with a time-varying load resistance are investigated both theoretically and experimentally. The sensitive element of the system under consideration is periodically connected to the input of the measuring device. The processes of accumulation and redistribution of electric charges in this case are similar to those in pyroelectric vidicons. Theoretical analysis is based on the expansion of input time functions into a family of elementary signals, such as delta or unit step functions. In this case the response to an arbitrary signal can be calculated as a superposition of the elementary responses. Output signal of such sensors is represented by a periodical sequence of impulses under sinusoidal thermal excitation conditions, contrary to a sinusoidal signal in the case of stationary systems. Operating conditions under which the output signal amplitude exceeds the stationary response and is independent of the load resistance value are found.