超敏感负阻开关组合晶体管

以往的负阻研究工计者,对S型负阻的研究仅局限于显型负阻,因此,其触发灵敏度受限制.1.两种S型负阻(1)显型负阻 其负阻曲线能够从晶体管图示仪上直接观察到的负阻,叫显型负阻,由两只β值为1的互补晶体管进行组合,就可得到显型负阻,如图1所示.     

大功率金属陶瓷四极管的负阻振荡

文章对四极管的二次电子放射进行了阐释,分析了产生负阻振荡的机理,并结合DF-100A PSM短波广播发射机发生的负阻振荡故障实例,阐述了负阻振荡的危害及防止负阻振荡的方法。     

新型恒压控制型负阻HBT的研制进展

研究了HBT产生负阻的可能机制,通过对材料结构和器件结构的特殊设计,采用常规台面HBT工艺,先后研制出3类高电流峰谷比的恒压控制型负阻HBT.超薄基区HBT的负阻特性是由超薄基区串联电阻压降调制效应造成的,在GaAs基InGaP/GaAs和AlGaAs/GaAs体系DHBT中均得到了验证.双基区和电阻栅型负阻HBT均为复合型负阻器件.双基区负阻HBT通过刻断基区,电阻栅负阻HBT通过在集电区制作基极金属形成集电区反型层,构成纵向npn与横向pnp的复合结构,由反馈结构(pnp)的集电极电流来控制主结构(npn)的基极电流从而产生负阻特性.3类负阻HBT与常规HBT在结构和工艺上兼容,兼具HBT的高速高频特性和负阻器件的双稳、自锁、节省器件的优点.     

双向负阻器件的数值模拟

本文通过对双向负阻器件进行数值模拟，分析了其产生负阻的内部图象，模拟结果表明，高阻集电区厚度的减小或衬底杂质浓度的增加使负阻曲线的摆幅增大，而基区掺杂浓度的提高将使负阻曲线的峰值减小。     

与HBT工艺兼容的新型负阻器件的研制与分析

在HBT工艺基础上,通过对器件结构的特殊设计,研制出了一类新型三端负阻器件,其恒压控制型负阻的PVCR大于800,并伴有恒流控制型负阻。通过atlas器件模拟软件进行模拟后对其物理机制进行了解释。该器件既能保持HBT高频、高速的特点,又具有负阻、双稳、自锁等特性,同时与普通台面HBT工艺兼容,易于集成,是一种具有研究和应用价值的新型负阻器件。     

一种互补结型场效应管负阻器件

介绍了一种利用集成互补结型场效应管的简单复合而构成的负阻器件，并且对该负阻器件的温度特性进行了分析，为设计具有温度稳定性的负阻器件提供了有益的参考。     

光电双向负阻晶体管的数值模拟与实验研究

光电双向负阻晶体管(PBNRT)是一种新型S型光电负阻器件.本文对它的光电负阻特性进行了数值模拟和实验研究,给出了器件等效电路.PBNRT在光电混合工作模式下具有光控电流开关效应,可通过光照和控制电压两种控制方式改变器件的S型负阻特性.模拟和实验结果均表明:光照强度增大,维持电压基本保持不变,转折电压减小,负阻电压摆幅减小;而增大控制电压,维持电压和转折电压均增大,输出负阻特性曲线右移.上述特点使得PBNRT可望在光电开关、光控振荡和光电探测等方面有很好的应用前景.     

微波单片有源滤波器负阻电路的实现方法

论述了用于微波单片有源滤波器负阻电路的实现方法，给出了三种由单管ＦＥＴ构成的负阻电路，以及用ＭＭＩＣ工艺能够实现的矩形螺旋电感与ＦＥＴ实现的负阻电路，并对电路进行了详细的分析与计算机模拟，分析与模拟结果显示用单管ＦＥＴ实现的负阻电路结构简单，在谐振频率点，最大负阻值可达几千欧姆，而且，综合出的负阻电路完全可以用现有的ＭＭＩＣ工艺实现，为进一步设计微波有源滤波器打下了良好的基础。     

三端双向负阻晶体管的二维数值模拟及分析

对双向负阻晶体管(BNRT)的三端特性进行了数值模拟，得到了器件S型负阻曲线。根据BNRT不同工作状态下的内部电势、电子浓度和空穴浓度分布，解释了其S型负阻特性的产生机理。模拟分析了负阻曲线随控制电压变化的情况。结果表明，随控制电压的增大，转折电压、转折电流和维持电压均增大。最后，对不同结构和工艺参数的三端BNRT进行了模拟，总结出器件结构和工艺参数对负阻特性的影响。     

MIM隧道发光结的负阻现象

本文介绍了薄膜隧道发光结的基本结构、发光机理，阐述了其Ｉ－Ｖ特性中的负阻现象。简单介绍了ＭＩＭ结构负阻的几种解释，根据热像仪照片和低温测试结果分析，再结合Ｄｅａｒｍａｌｅｙ导电模型，我们提出了ＭＩＭ负阻的物理模型，理论与实验符合较好，最后分析了负阻现象的应用前景。     

CoMnNiO系NTC热敏半导体陶瓷烧结特性与电性能研究

研究了CoMnNiO系负温度系数热敏电阻陶瓷材料的烧结特性和电性能,探讨了不同烧结方法对CoMnNiO系NTC热敏陶瓷烧结特性及电性能的影响。试验结果表明,微波烧结的样品成瓷均匀、致密,且晶粒较小。对其电性能进行研究发现:同样温度下微波烧结制备的热敏元件B值、阻值一致性较常规烧结方法有较大提高。由此可见,微波烧结技术在制备热敏电阻陶瓷材料方面具有潜在的优势。     

Positive Female Role‐Models Eliminate Negative Effects of Sexually Violent Media

Much debate has focused on the potential negative role of sexualized violent media on viewer attitudes toward women. One potential issue in previous literature is that depictions of sexuality and violence were confounded with subordinate depictions of female characters. The current study addressed this by randomly assigning young adults to watch either neutral media or sexually violent media with either subordinate or strong female characters. Women who watched sexually violent media were more anxious, and males who watched sexually violent media had more negative attitudes toward women, but only when female characters were subordinate. Sexual and violent content had no influence on viewer attitudes when strong female characters were present, suggesting these are not the crucial influence variables.     

对负电阻及其应用的研究

负电阻在电路分析、电工学、电子技术中应用广泛，本文通过运算放大器实现了负电阻，画出了负电阻的伏安特性曲线，讨论了负电阻与负电阻的串并联关系，负电阻与正电阻的串并联关系，得出结论：它们的串并联关系遵守串并联法则，遵守欧姆定律。但负电阻的串并联能改变它们的正负关系。负电阻既可吸收功率．又可释放功率，但负电阻不能单独作用。     

Observation and analysis of negative resistance in the forward I-V characteristics of dielectrically isolated high-voltage gated diode switches

A current-controlled negative resistance in the forward current-voltage characteristics is observed on some dielectrically isolated gated diode switches (GDS). Defect etching of the devices that exhibited negative resistance showed a high density of defects compared to devices that did not. The high density of defects in the cathode implied a possible resistive shunting of the n⁺-p junction. To verify this, special test structures were used with an external resistor shunting of the n⁺-p cathode to simulate the effects of defects. TheI-Vcharacteristics of the GDS with the externally connected resistor shunt exhibited negative resistance similar to that with high defect density devices. When the external shunt was removed the characteristics did not show any negative resistance. Thus we infer that the cause of the negative resistance in our original samples is the resistive shunting effect of the defects in the cathode. A simple physical model for the negative resistance is presented and corroborated with our experimental observations.     

E型左手材料

由于E型结构具有产生负磁导率所需的等效电感和等效电容,据此提出一种新型左手材料,用E型SRR来实现负的磁导率,金属线结构来实现负的介电常数。等效模型分析证实这个结构确实能够实现稳定的左手特性。有限元法仿真并用S参数法提取等效介电常数、等效磁导率和折射率,得到样本在11.5～14GHz频段内具有明显的负折射率特性。棱镜折射实验也再次证明了该结构的负折射率特性。     

一种有效减缩微带天线RCS的新方法

根据经典理论,对于线极化矩形贴片天线,其主模电场强度在平行于非辐射边的中心线上为零。如果沿此中心线对微带天线加载电阻,对其辐射性能影响不大,然而对散射性能则有很大改善。通过引入一种阻抗加载技术和接地板开槽技术使微带天线的RCS大幅减缩,结合小型化技术,微带天线的RCS得到进一步减缩,而且天线外形尺寸也比原天线有所减小。这样,就同时兼顾了微带天线的辐射性能和散射性能。     

A current-controlled negative-resistance effect in indium antimonide

A thin wafer of P-InSb exhibits a current-controlled negative resistance between nonsymmetrical ohmic contacts on opposite sides of the wafer. The small contact on one side of the wafer is made positive relative to the large contact on the other side. Most effective samples had small contact diameters one to four times the slab thickness. The negative resistance was present up to a temperature of 210°K for material having 2.5 × 10¹⁴/cm³acceptor concentration at 77°K. A magnetic field perpendicular to the current flow direction reduced the value of the maximum negative resistance and extended the range of bias current yielding negative resistance. Samples under 0.005 inch thick yielded negative resistance when operated continuously, for the doping of 2.5 × 10¹⁴/cm³, but thicker samples yielded negative resistance only in lower duty cycle operation. Microwave radiation lines presumably at harmonics of oscillation in the bias circuit were measured. Finally, a proposed mechanism, dependent on impact ionization, is used to predict operation to a transit-time limited frequency of, say, 8000 Mc/s for a sample whose thickness is 0.0025 inch.     

Varactor-tuned active bandpass filter with low noise performance

An active tunable bandpass filter based upon the negative resistance method using a microstrip combline network is presented. The negative resistance is realised using a common-drain series feedback structure. 0.4 octave tuning with significant improvement in passband performance was achieved and the noise performance was comparable with its passive counterpart.