A method of suppressing self-heating signal of bolometers

A scheme of full self-heating compensation for the bolometer-based infrared (IR) sensors was proposed. Infrared-sensitive and infrared-insensitive bolometers with nearly identical self-heating characteristics were connected in parallel in a Wheatstone bridge to suppress the common mode. The time-dependent component of the output signal due to the self-heating effect was substantially limited. The effectiveness of the scheme was demonstrated by testing of micromachined bolometers. The output signals from the bridge were fed into a differential amplifier and the self-heating component of the output signal dropped from 34 to 1.5 mV. The signal was then dominated by the IR radiation response. The proposed scheme enabled signal integration time to increase for the purpose of signal-to-noise ratio improvement.