高温超导红外测辐射热计

根据超导测辐射热计的理论，以YBCO为材料，制备的高温超导薄膜型红外测辐射热计，黑体响应度Rv＞104V／W，D*＞1010cmHz1／2W－1，NEP≈10－14WHz-1／2。测量和分析了器件的频率响应、噪声特性和其对1～15μm波段及118．8μm，337μm，570．5μm，699μm，1009．4μm等波长的光谱响应。测量结果表明，高温超导红外测辐射热计对整个红外波谱都有响应，但其性能在远红外波段衰减很厉害，因此，对器件的表面处理应是提高其长波性能的一个关键。     

非致冷测辐射热计的数学模型

总结了非制冷测辐射热计的经典数学模型,并分析了探测器热绝缘结构和噪声对性能的影响,指出了性能改进和优化的基本途径.     

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.     

非致冷测辐射热计的研制方案

介绍一种基于氧化钒（ＶＯｘ）测辐射热计探测器的红外焦平面阵列（ＩＲＦＲＡ）,叙述了它的材料、制作方法、探测器列阵、真空封装和器件性能等有关问题,并与其它与非致冷热电焦平面阵列进行了比较。氧化钒（ＶＯｘ）测辐射热计ＩＲＦＰＡ可构成高质量的红外热像仪,非常适合于军事和民品的广泛应用,在下一个十年这项技术有望发展成为一种新的产业。     

微测辐射热计的优化设计

针对典型的50 μm×50 μm双层微桥结构的微测辐射热计单元的设计,分析了其红外吸收性能、热性能、力学支撑性能及相互间的折衷关系,指出微桥桥面的夹层结构的各层膜厚选取和桥腿宽度的选取是兼顾红外吸收和热、力性能的关键因素.以Si3N4/VOx/ Si3N4膜系为例对微桥进行了优化设计,获得了理论上最佳的夹层结构膜厚和桥腿宽度,得到时间常数20 ms和8-14 μm波段有80 %以上红外吸收率.     

非制冷红外微测辐射热计的研制

采用多晶硅薄膜材料作为热敏电阻材料，以普通的ＩＣ工艺及微机械加工技术研制成功了在室温下工作的红外微测辐射热计，其多晶硅电阻温度系数为－２％℃－１，探测率Ｄ＊达２×１０８ｃｍ·Ｈｚ１／２·Ｗ－１．     

微测辐射热计阵列结构的制备

为了研究和优化二氧化钒（VO2）微测辐射热计的制备工艺,采用微电子机械系统（MEMS）体硅工艺制备了VO2微测辐射热计,经过研究和改进制备工艺,制得的微测辐射热计结构稳定,成品率高;经测试及计算,其响应率可达34.3kV/W,探测率为1.2×10^8cm.Hz1/2/W,响应时间约为65.3ms。此器件性能达到国内外同类器件水平。     

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。     

测辐射热计红外焦平面列阵

非制冷测辐射热计红外焦平面列阵设计为桥式结构,器件制作采用微机械加工技术。工作被段为８￣１２μｍ,热阻达１０＾７Ｋ／Ｗ量级,噪声等效温差为０．１Ｋ。     

Harmonic and Intermodulation Performance of the Semiconductor Bolometer

A mathematical model for the temperature dependence of the bolometer semiconductor resistance is presented. The model, basically a sine-series function, can easily yield closed-form expressions for the harmonic and intermodulation performance of the acquired interferogram voltage with large-amplitude multisinusoidal variations in the incident radiation. The special case of two-tone equal-amplitude incident radiation is considered in detail. The results show that the intermodulation components are always higher than the harmonic components of the same order. The results also show that the second-order intermodulation is always dominant and is higher than the second-harmonic component by about 6 dB. Moreover, the results show that for relatively small incident amplitudes of the incident radiation the ratio between the second- and third-harmonic components is almost equal to the ratio between the second-harmonic component and the fundamental. The results also show that the ratio between the amplitudes of the second- and third-order intermodulation components is almost equal to the ratio between the amplitudes of the second-order intermodulation component and the fundamental.     

测辐射热计微桥结构的形变分析

采用微加工技术制作测辐射热计阵列时,部分微桥可能发生结构变形,使阵列的性能下降甚至无法正常工作.采用有限元分析方法,对在热膨胀和薄膜应力影响下的I型和L型两种微桥的变形进行了仿真分析,揭示了热膨胀和薄膜应力分别对微桥形变的影响.     

Modelled V-I Performance of A 3HE Composite Bolometer Detector

The V-I characteristics of a ³He-cooled, composite bolometer detector designed for submillimetre astronomy are modelled. The modelling yields detector parameters that cannot be measured directly. The system NEP predicted from theoretical V-I equations is found to agree with the measured noise values. The calculated dynamic thermal conductance and the electrical responsivity are found to deviate from the standard model at low temperatures.     

High-Efficiency Millimeter-Wave Bolometer Mount

A bolometer mount is described for measuring TEO/sub 01/-mode waveguide power at a frequency of 100 GHz. This device is called an eight-fan-type bolometer mount. By dividing the electrode of the element into eight segments, the generation of an unwanted mode was suppressed, and, by minimizing the electrode area, heat loss due to the electrode was decreased. As a result, good matching characteristics and high effective efficiency were obtained. This mount is sufficiently useful for a precision power measurement in the millimeter-wave region.     

一种用于探测太赫兹信号的测辐射热仪

基于Nb5N6薄膜在室温下具有高达-0.7％ K-1的电阻温度系数,用Nb5N6薄膜结合平面蝴蝶结天线制备了一种可在室温下进行100 GHz信号探测的测辐射热仪.该器件在偏置电流为0.4 mA的条件下,达到的最佳电压响应为-400 V/W,调制频率为200 Hz时等效噪声功率达到1.5 ×10-11 w/(√Hz),调制频率10 kHz以上时等效噪声功率优于9.5×10-12W/(√Hz).     

非致冷测辐射热计红外焦平面阵列

非致冷测辐射热计以其高性能和低价格 ,成为红外热成像技术新的研究热点。焦平面设计为桥式结构 ,器件制作采用微机械加工技术。文章介绍了该器件的设计、制作、性能和应用。     

Equivalent Circuit of the Bolometer Detector

A small-signal dynamic equivalent circuit is established for the output voltage of a dc-biased bolometer (barretter) detector. The circuit consists of a voltage generator /spl upsi//sub g/, whose output is an undistorted replica of the incident RF-power modulation envelope, followed by a series resistor R/sub 1/ of dynamic origin, a shunt capacitor C that represents heat storage in the bolometer wire, and a series resistor R/sub 0/ equal to the dc resistance, usually 200 ohms. The resistance R/sub 1/ is independent of signal level, and is typically about 220 ohms for an 8.75-mA bolometer and about 120 ohms for a 4.5-mA bolometer. At a modulation frequency f/sub m/ near 0 Hz, the equivalent audio source impedance of the bolometer is R/sub 1/ +R/sub 0/. The common belief that the source impedance is R/sub 0/ in the weak-signal case is, therefore, refuted. Formulas are derived giving v/sub g/ / /P/sub RF/ and R/sub 1/ as functions of basic, easily determined bolometer parameters. The time constant for open-circuit load is /spl tau//sub oc/= R/sub 1/C, where /spl tau//sub oc/ is determined best by measurement, since catalog values of /spl tau//sub oc/ often are seriously in error. The capacitance is C=/spl tau//sub oc/ / /R/sub 1/. With one type of bolometer /spl tau//sub oc/ measures about 110 /spl mu/s, while various catalogs state values of 250 to 350 /spl mu/s. The equivalent circuit is confirmed quantitatively by measurements of output voltage and source impedance versus modulation frequency.     

国外模拟保密机剖析

本文剖析了国外6种模拟保密机,它们的置乱技术均采用以时段置换为主,结合简单的频域处理。其设计思想、参数选择以及其它有关技术可供国内研制模拟保密机时参考。