Electro-thermal Feedback Effects on the Signal in a Pulse Voltage Biased μ-bolometer Focal Plane Array

Abstract

-In this paper, the analytical models for the electrothermal feedback of a µ-bolometer focal plane array(FPA) are proposed and applied to the conceptually designed FPA to investigate the electrothermal feedback effect on bolometer FPA signal. The temperature and resistance change of the µ-bolometer by the electrothermal feedback(ETF) model are increased upto 20 and 35.7 % of those of no feedback case, respectively, while those by the effective thermal conductance(ETC) model increased 8.5 and 15.1 %. The integration current and output voltage of a CTIA used as an column amplifier of FPA are also increased upto 41.6 and 32.4 % by the ETF model, while increased upto 17.2 and 13.5 % by the ETC model. The proposed models give more accurate temperature change, accordingly larger signal than no feedback considering case. Electrothermal feedback effect should be considered to design a high performance and high density µ-bolometer FPA. The proposed models are very useful to investigate the transient thermal analysis, also considered to be useful to predict the responsivity and dynamic range of µ-bolometer FPAs.

Analytical model for the electro-thermal feedback effect in a microbolometer infrared focal plane array

“…The characteristics of the microbolometer IRFPA used for this study are summarized in Table 1. [16][17][18][19] The temperatures of the microbolometer calculated by the CL, FAG, and ETC models, respectively, are shown in Fig. 1.…”

“…[16][17][18][19] The IR response signals can be predicted from the resistance changes calculated with each model. Figure 3 shows the predicted IR response signals of the previous microbolometer IRFPA of Table 1.…”

“…[13][14][15][16][17][18][19] ΔT ¼ T d − T a . Also, T d , T a , and P are the detector temperature, the constant ambient temperature, and the heat source, respectively.…”

“…Hence, the correct understanding of the electro-thermal effect leads not only to a more accurate signal prediction in the development, but also to the proper use of an IRFPA in the application period. [13][14][15][16][17][18] In this article, two analytical models for the electro-thermal feedback effect in the microbolometer IRFPA are presented. The electro-thermal feedback effect starts when the bias is applied to read the resistance change of the microbolometer in IRFPA.…”