微测辐射热计响应率的数值分析

介绍了微测辐射热计在外加偏置下的响应情况，建立了流偏置下微测辐射热计的响应率模型，及脉冲偏置下微测辐射热计的完整理论模型，进行了数值分析，给出了在实际工作条件下微测辐射热计响应率的仿真结果。     

微测辐射热计的等效模型

微测辐射热计是一种应用前景广阔的非致冷型红外焦平面器件.这里用热平衡理论和噪声理论详细分析了微测辐射热计探测单元的热学、电学和噪声特性.建立了较为全面的微测辐射热计探测单元Spice模型,并对该模型进行了热学行为和噪声特性的仿真,由仿真结果对探测单元的工作方式和特性建立了具体、直观的认识,为下一步的设计工作打下了坚实的基础.     

金属微反射镜对非制冷氧化钒微测辐射热计的红外辐射吸收率影响分析与一种改进的微测辐射热计模型

从光学角度出发,首先讨论了单层VOx微测辐射热计中探测单元衬底上的金属反射镜的厚度以及材料对微测辐射热计红外吸收率的影响,利用软件建立了微测辐射热计的红外辐射吸收率模型,得到了厚度不同的Al反射镜对微测辐射热计模型8~14?m红外波段吸收率的影响以及厚度为0.1?m的3种不同材质的金属反射镜对同一模型红外吸收率的影响。当厚度等其他参数相同时,使用Al、Copper和Gold用作金属反射镜的材料,单层VOx微测辐射热计模型在8~14?m波段的红外吸收率并没有明显区别。另外,我们改进了一种已有的VOx微测辐射热计结构并对比了改进前后模型8~14?m红外波段的吸收率,改进后的模型平均吸收率达到了94%大于改进前初始模型的90%左右。最后,我们讨论了真空谐振腔高度与微测辐射热计桥面材料厚度对工作波段吸收率峰值处波长的影响。     

非制冷微测辐射热计的热平衡分析

非制冷微测辐射热计焦平面阵列技术在国外已取得了令人瞩目的成就,与其它红外探测器相比,微测辐射热计更适于开拓民用市场,目前国内在这方面的研究也已成为热点。文章介绍了微测辐射热计的物理模型及其理论计算方法,利用黑体辐射和传热理论,建立了微测辐射热计的热平衡方程,并利用MATLAB软件获得了数值运算结果。分析表明,热传导、热容、偏置方式等时微测辐射热计性能的影响是设计考虑的关键。     

一种具有衬底温度补偿功能的非制冷红外读出电路

针对非制冷红外探测器系统,设计了一种无需衬底温度稳定器——热电制冷器(TEC)的读出电路(ROIC)结构.首先分析了衬底温度对微测辐射热计的特性的影响,利用ROIC对衬底温度变化引起的微测辐射热计的特性的变化进行补偿,实现ROIC的输出信号与衬底无关.该ROIC已在0.5 μm CMOS工艺下成功流片,并应用了到阵列大小为320×240的非制冷微测辐射热计焦平面上.测试结果表明:在衬底温度变化20 K时,ROIC输出信号仅变化2 mV,实现了去除TEC后衬底温度补偿的功能,有效地降低了系统功耗.该ROIC在低功耗,小体积的非制冷红外探测器上有着广泛的应用.     

基于非晶硅薄膜的微测辐射热计光学仿真和优化

基于非晶硅薄膜的非制冷微测辐射热计具有结构简单、易于大规模集成、工艺兼容以及良好探测性能等特点,在红外探测领域等受到关注。引入氮化钛薄膜作为新型红外吸收材料,通过光学导纳矩阵法,对基于非晶硅薄膜的微测辐射热计的红外吸收特性,进行了仿真和优化研究。结果表明,非晶硅微测辐射热计中,氮化钛/非晶硅复合薄膜具有良好的红外吸收性能。当非晶硅薄膜厚度为120 nm时,由氮化钛/非晶硅组成的膜系在8～14μm范围内具有96%左右的红外吸收率,其中氮化钛薄膜的最佳吸收厚度为32nm。     

微测辐射热计的红外热响应模拟

利用有限元法对微桥结构的测辐射热计进行了二维热模拟.定量地分析了探测单元的大小尺寸、支撑层的厚度,支撑臂的长度和宽度、引线材料的选取等对微测辐射热计探测单元在红外辐射下温度的变化和热响应的快慢情况.评估了真空封装对微测辐射热计红外响应的影响.同时作为比较对平板空腔结构的红外探测器也进行了分析.     

非制冷微测辐射热计热成像

文中在指出现代制冷型红外成像技术的不足,论述非制冷红外成像技术的优点之后,介绍了微测辐射热计阵列的非制冷热成像系统.首先与非制冷热电热像仪进行了比较,指出测辐射热计热成像的优势.然后描写了微测辐射热计阵列的设计,分析了桥式结构热绝缘对响应率提高所起的作用,并讨论了探测器噪声等效温差(NETD)的性能.最后概括地描述了微测辐射热计成像仪的设计.     

红外成像器 美国专利US7247850（2007年7月24日授权）

本发明提供一种可用来探测光学系统视场中场景的红外辐射并将红外辐射转换成可见光图像的红外成像器。该红外成像器由位于光学系统焦平面中的一个非致冷微测辐射热计列阵和一个发光二极管或液晶显示元件列阵组成。其工作原理是，微测辐射热计收集到的红外辐射使其电输出发生变化，     

测辐射热计性能的模拟分析

介绍了测辐射热计红外探测器,并从理论上对测辐射热计的热流量进行了模拟计算,得出由膜电阻实现的光电变换的输出信号电压,继而分析了测辐射热计的响应率和灵敏度等性能。指出了选用具有大的电阻温度系数和膜电阻材料和优良的热绝缘结构（如桥式结构）是研制器件的关键．测辐射热计具有性能好、价格低、可靠性高的特点,采用它研制的轻小型低功耗的红外热像仪可广泛地用于军事和民品。测辐射热计技术有望在下一个十年发展成为一门     

非致冷微测热辐射计阵列的设计

非致冷微型热辐射计焦平面阵列技术在国内已成为研究热点。介绍了微测热辐射计的原理并对其作了简化的计算分析,给出了微测热辐射计的结构、材料、封装和读出电路等重要部分的一些设计方案。     

Ultra-low-noise readout integrated circuit for uncooled microbolometers

A low-noise readout architecture for uncooled microbolometer focal plane arrays is described. A 40times30 uncooled microbolometer focal plane array based on the low-noise ROIC was implemented on silicon using a 0.5 mum CMOS technology. Total output noise voltage is 260 V RMS. Experimental values of voltage responsivities of 3.98 10⁵ V/W on average at 1 Hz modulation frequency have been achieved.     

氧化钒热敏薄膜非致冷红外探测器的等效模型

建立了氧化钒热敏薄膜微测辐射热计的PSPICE模型，结合一个具体的CMOS读出电路给出探测器的等效电路模型，分析了探测器的电学和噪声特性，根据等效模型基于微测辐射热计电阻RD和读出电路MOS沟道宽度形两个设计参数对噪声等效温差（NETD）进行了优化，优化数据表明，折中选取参数RD和W对探测器性能有重要的意义。     

CMOS readout circuit allowing microbolometer arrays to operate without temperature stabilisation

A new CMOS readout circuit that controls the non-uniformity of microbolometer arrays as a function of operating temperature change is described. This circuit provides a nonlinear bias current for operating temperature using a MOS transistor that is operated in the subthreshold region. This approach allows microbolometer arrays to operate without temperature stabilisation up to an operating temperature change of approximately 40K.     

Pixelwise readout circuit with current mirroring injection for microbolometer FPAs

A pixelwise readout circuit for application in microbolometer focal plane arrays (FPAs) is studied. A current mirroring injection input circuit that is suitable for a pixelwise architecture and has high responsivity is proposed. The noise equivalent temperature difference can be improved to 31 mK.     

CMOS circuit for readout of microbolometer arrays

A CMOS circuit for the readout of microbolometer arrays is presented. It provides a pulsed bias for the microbolometers, signal amplification and multiplexing to a common output. The chip can be used with linear and small two-dimensional arrays of microbolometers realising a hybrid infrared sensor     

An ultra low noise readout integrated circuit for uncooled microbolometers

A low noise readout architecture for uncooled microbolometer focal plane arrays is described. The on-chip readout circuit contains an integration circuit in which the bolometer current is directed injected into a capacitor, and exhibits extremely low noise with no decrease in signal by using an ultra low noise capacitive transimpedance amplifier (CTIA). The simple configuration of the integration circuit makes it possible to operate more circuits in parallel, and increases the integration time and number of pixels. A 40 × 30 uncooled microbolometer focal plane array based on the low noise ROIC was implemented on silicon using a 0.5 μm CMOS technology. The total output noise voltage is 260 μV RMS. A noise at this level is so low that can loosen required TCR in the bolometer material. Experimental values of voltage responsivities of 3.98 × 10⁵ V/W on average at 1 Hz modulation frequency have been achieved.     

一种红外焦平面非均匀性校正改进方法的研究

微测辐射热计吸收入射红外辐射，引起读出电路输出信号的非均匀性。由于非均匀性校正的局限性，以前的微测辐射热计需要对基底温度进行精确控制。文中在两点校正法的基础上，提出了偏置校正法，可以放松对基底温度控制的要求。在常规两点增益与补偿校正法基础上，采用偏置校正，可以更宽的基底温度范围内进行非均匀性校正。这样的话，在读出电路片上进行基底温度控制是可能的。     

An Ultra-Low Noise Superconducting Antenna-Coupled Microbolometer With a Room-Temperature Read-Out

In this letter, we report the electrical and optical characteristics of a superconducting vacuum-bridge microbolometer with an electrical noise equivalent power of 26fW$sqrthboxHz$and an effective time constant of 380ns, when operated at a bath temperature of 4K. We employ a novel room temperature external negative feedback readout architecture, that allows for noise matching to the device without bulky stepup transformers or cooled electronics. Both the detector and the readout lend themselves to be scaled to imaging arrays. The directly measured noise equivalent temperature difference over a 100–1000-GHz bandwidth is 125mK in a 30-ms integration time.     

Nonoptical characterization techniques for uncooled microbolometer infrared sensors

Infrared image sensors based on micromachined microbolometers can be integrated with CMOS addressing, readout, and signal processing circuitry. Testing of such sensors in the commercial environment must be rapid and cost effective, hence, other diagnostic techniques are preferred to optical testing wherever possible. Accordingly, this paper presents nonoptical techniques for characterising microbolometer-based IR sensors. From measurements of microbolometer resistance, thermal conductivity, and temperature coefficient of resistance, sensor fixed pattern noise and temperature response nonuniformity are determined. These measurements also provide feedback on the fabrication process parameters and defects.