Low power uncooled 120x160 a-Si-based micro infrared camera for unattended ground sensor applications

Low power and low cost are primary requirements for an imaging infrared camera used in unattended ground sensor arrays. In this paper, a 120x160 amorphous silicon (a-Si) microbolometer-based uncooled infrared camera technology offering a low cost, low power solution to infrared surveillance for UGS applications is presented. A 120x160 micro infrared camera (MIRC) has been demonstrated which exhibits an fil noise equivalent temperature difference (NETD) sensitivity similar to 63 mK. This sensitivity has been achieved without the use of a thermoelectric cooler for array temperature stabilization thereby significantly reducing the power requirements. Chopperless camera operation at a 20 Hz frame rate with power consumption of 380 mW has also been demonstrated. The 120x160 MIRC operates under digital signal processor (DSP) control. To reduce cost, this DSP-controlled architecture employs commercial off-the-shelf DSP, A/D, memory and voltage regulator chips. The detector chip, employing an integrating amplifier per unit cell ROIC design, is the single custom chip used. The camera also employs low cost f/1 optics, as well as low cost wafer-level vacuum packaging. In this paper, a-Si microbolometer technology for the MIRC will be presented. Also, the key features and performance parameters of the MIRC are presented.