二十四所射频及模拟放大器集成电路发展历程与展望

回顾了二十四所射频及模拟放大器集成电路专业方向的发展历程，并对未来发展进行了展望。按不同历史阶段，介绍了二十四所在集成运算放大器／比较器、中频／视频线性／非线性放大器、MMIC、集成射频放大器等产品类别所取得的主要成就；并对高性能模拟放大器IC技术的发展进行了讨论。     

γ射线式密度传感器及其在石油勘探中的应用

】γ射线式密度传感器由于其独特的优点而受到国内外用户的重视。文章首先分析了这种传感器的工作原理，在此基础上对其关键电路———前置放大器进行了重点讨论。最后说明了采用上述传感器测量泥浆密度的实际效果。     

一种可变阶次模拟分抗电路的实现方案

在分数阶微积分的工程应用中,一个最重要的步骤是模拟分抗电路的实现,为此采用跨导运算放大器设计了可变阶次分抗电路,并利用有限数量的二端口网络级连,能够在电路设计形式固定的情况下,通过调节跨导运算放大器的控制电流,在一定的范围内改变分抗的运算阶数。模拟结果与理论分析结果相一致,证明该设计方案对于分数阶微积分的实际应用有着一定的工程意义。     

Carbon nanotubes field emission integrated triode amplifier array

Because the high frequency operation of a field emission triode amplifier is dictated by the cutoff frequency and not the electron transit time, a high ratio of transconductance, g_m to the overlapping interelectrode capacitance, C_g is the desired outcome. Consequently, to achieve high frequency performance of the CNT amplifier array in this study, C_g was reduced by performing a dual-mask photolithography process to minimize the overlapping gate area, and, the insulating layer's thickness was increased. Moreover, wedge-shaped CNT emitter arrays are employed to increase emission sites, resulting in return higher g_m. Both dc and ac performance of the amplifier were characterized. The triode amplifier array exhibited a high current of  0.32 mA (74 mA/cm²), g_m of  63 μS and voltage gain of  18 dB. Frequency response of the triode amplifier up to 20 kHz was also investigated. A theoretical cutoff frequency of > 70 MHz could be achieved with proper shielding of the test setup.     

混合集成大动态低噪声前置中频放大器

主要介绍大动态低噪声前置中频放大器ＳＨ３０１电路的设计及典型应用参数。通过采用大动态高频晶体管提高放大器的输入动态范围；采用便于调整的单级双负反馈电路来实现阻抗匹配和高的增益精度；运用计算机ＳＰＩＣＥ程度进行参数优化设计。根据新设计电路的特点，采用厚膜混和集成工艺，研制的ＳＨ３０１电路达到了较高的水平。     

混合集成低噪声宽带AGC放大器

采用厚膜混合集成工艺，研制出ＳＨ３０９－１低噪声宽带ＡＧＣ放大器，其噪声系数≤１．５ｄＢ，最大输入电平≥４００ｍＶ／５００Ω，增益≥５０ｄＢ，增益控制范围≥５０ｄＢ，工作频率范围为６０ＭＨｚ±１０ＭＨｚ。主要介绍了其设计原理及应用。     

微型组装的级联对数放大器

本文结合对数放大器在雷达接收机中的应用,采用微型组装级联单片对数放大器的方法,来扩大动态范围,提高对数精度,从而获得适当的频带和传输时延。文中列出了微型组装的五级、六级和七级级联对数放大器的测试结果。     

一种低噪声高增益宽带视频对数放大器

着重介绍了一种用于电子对抗系统预警雷达接收机中的低噪声高增益宽带视频对数放大器的设计原理，制造工艺及其应用，进一步考察了国内外整机系统的发展现状，综合介绍了目前国内外视频对数放大器的发展及其在整机系统中的应用前景。     

光电探测器的设计

分析了硅光电二极管的基本结构，等效电路，噪声等情况，为了提高测量时的线性，要选取Ｒｄ大，Ｒｓ小，ｉ０小的硅光电二极管，并在输出短路状态下工作。因此常采用将运算放大器接成电流－电压转换器的办法来满足这一要求。分析了运算放大器的噪声电压，噪声电流，失调电压，失调电流和硅光电二极管的噪声因素对硅光电二极管与运算放大器组合电路的影响。考虑这些因素可以设计出响应快，灵敏度高，稳定度好，测量线性好，信噪比高的     

Transmutation capabilities of the CERN Energy Amplifier System

Progress in particle accelerator technology makes it possible to use a proton accelerator to produce energy and to destroy nuclear waste efficiently. Energy Amplifier (EA) systems consist of a sub-critical fast neutron core driven by a proton accelerator. If well designed, they prevent any possible criticality accidents. It has been proposed to take advantage of this sub-criticality in order to use certain types of fuel with poor neutronic properties (for instance those with very small delayed neutron fractions). In this respect, they are particularly attractive for destroying, through fission, transuranic elements produced by present nuclear reactors. EA's could also transform efficiently and at minimal cost long-lived fission fragments using the concept of Adiabatic Resonance Crossing (ARC), an innovative method tested at CERN with the TARC experiment.