Study of the conductance of ultrathin tin diphthalocyanine films

The frequency dependences of the conductance and capacitance of Langmuir-Blodgett tin diphthalocyanine films in vacuum and in the case of adsorption of water molecules were studied. An increase in the film conductance due to adsorption was detected. Possible conduction mechanisms of tin diphthalocyanine in vacuum and water vapor are discussed. The permittivity of tin diphthalocyanine films was estimated from an analysis of the frequency dependence of the capacitance.     

Study of the transport properties of organic semiconductors based on europium diphthalocyanine and bi-tris-phthalocyanine complexes with <Emphasis Type="Italic">ortho</Emphasis>-bis(oxymethyl)phenyl bridge and based on erbium and europium dinaphthalocyanine complexes

The transport properties of organic semiconductors based on europium diphthalocyanine and bitris-phthalocyanine complexes with ortho-bis(oxymethyl)phenyl bridge and based on europium and erbium dinaphthalocyanine are studied. The temperature dependences of the dc conductivity for all types of the structures under study are obtained; it is shown that all dependences include two activation portions. For high-temperature portions, the activation energies are determined as 0.85 eV for europium diphthalocyanine with the ortho-bis(oxymethyl)phenyl bridge, 1.135 eV for europium bi-tris-phthalocyanine with the orthobis(oxymethyl)phenyl bridge, 0.98 eV for europium dinaphthalocyanine, and 1.18 eV for erbium dinaphthalocyanine. For the low-temperature activation portion, it is shown that lanthanide ions and their bond with a ligand make the dominant contribution to the conductivity of the structures under study.     

Solid-state anion migration in the anodic oxidation of lutetium diphthalocyanine

The solid-state anion-migration mechanism proposed recently to account for the results of moving-boundary measurements on lutetium diphthalocyanine films was confirmed by quantitative radiotracer experiments using chloride and sulfate electrolytes. The same mechanism was independently demonstrated for these anions and for bromide by semiquantitative energy-dispersive x-ray spectroscopy. The red oxidation product containing chloride ion decomposed gradually in ambient air, while that containing sulfate or bisulfate appeared to be stable. This paper was presented in part at the 21st Electronic Materials Conference in Boulder, Colorado, June 27, 1979.     

Red shift in optical absorption of erbium and dysprosium diphthalocyanine thin films on exposure to chlorine

The optical absorption characteristics of vacuum-deposited thin films of erbium and dysprosium diphthalocyanine were investigated using transmission spectroscopy before and after exposure to chlorine gas and compared with previous work performed upon lead monophthalocyanine (PbPc). Considerable red shifts in the visible absorption spectra were observed after Cl₂ exposure for the diphthalocyanines but not for the monophthalocyanine. These were interpreted on the basis of differences in molecular structure in relation to the adsorption of chlorine.     

Features of the spectral dependences of transmittance of organic semiconductors based on tert-butyl substituted lutetium phthalocyanine molecules

Vibronic properties of organic semiconductors based on tert-butyl substituted phthalocyanine lutetium diphthalocyanine molecules are studied by IR and Raman spectroscopy. It is shown that substitution of several carbon atoms in initial phthalocyanine (Pc) ligands with ¹³C isotope atoms causes a spectral shift in the main absorption lines attributed to benzene, isoindol, and peripheral C-H groups. A comparison of spectral characteristics showed that the shift can vary from 3 to 1 cm⁻¹.     

VME总线数据上行中断传输及从设备接口设计

介绍了VME总线数据的传送方式,分析了VME总线中优先中断总线的相关功能模块,研究了VME总线数据中断方式传输的机制,提出了一种基于中断方式数据上行传输的从设备VME接口的设计方法,给出了设计实例。     

石英MEMS陀螺的结构特性分析

介绍了石英微机电系统(MEMS)陀螺的工作原理及敏感芯片的音叉结构特点,采用有限元法分析了敏感芯片的结构特性,并对结构进行优化。利用石英晶体的压电效应,设计了合理的电极布局,并结合敏感芯片结构特点介绍了其微机械加工工艺。通过结构优化和合理的电极布局,提高了石英MEMS陀螺的性能。     

基于Credence Gemini500的内嵌式AD转换器测试方法研究

本文中应用Credence公司的Gemini500测试系统对某一SoC芯片内嵌模数转换器进行了测试。根据芯片功能分析和封装形式,对测试板进行了优化设计。根据内嵌式ADC的时序特点进行了测试向量的设计。     

声体波谐振器压控振荡器

声体波谐振器(FBAR)压控振荡器(VCO)技术探讨了高品质因数Q谐振器并实现宽频率调谐难题,完成了声体波谐振器MBVD模型参数建立、电路的选择与布局,以及最优化的设计与制作,尽量消除了FBAR与IC之间的引线产生的影响,克服了频率调整问题.研制了中心频率2.1GHz的VCO振荡器,研究结果表明,其输出功率为5～10 dBm,调谐范围为2.044‰,边带相噪为-143 dBc/1 Hz@1 MHz.     

介电型EAP驱动的转动关节研究

基于介电型电活性聚合物(EAP)的优点,设计、实现了该材料驱动的转动关节。根据介电型EAP的变形原理设计、制作了圆柱形驱动器,其输出最大位移约为11mm,伸长应变达到33.8%,并对输出力-位移特性进行测试。基于该型驱动器实现了转动关节,转角约为±13°,堵转力矩为19.6mN.m,将转动关节应用于爬行机器人,并对试验结果进行分析。     

基于LTCC工艺双频GPS陶瓷微带天线研究

在空腔模型理论基础上,利用微扰法对切角矩形微带天线进行严密的数学推论.并设计了GPS双馈点双频圆极化陶瓷微带天线.根据设计公式计算出结构参数,在Ansoft-HFSS软件中建立天线模型,通过参数优化得到天线参数,并利用LTCC工艺进行样品制作.结果表明:样品天线工作在1575 MHz和1 227 MHz时,10 dB带宽均大于10 MHz,回波损耗均小于-15 dB,轴比均小于4 dB,仿真结果与测试结果相似.总结了天线小批量生产的经验,提出了进一步小型化的研究方向.     

Modeling of noise for p-channel DG-FinFETs

The noise performance of p-channel Double Gate FinFETs has been studied with varying structural parameters. The effects of mobility degradation due to velocity saturation, carrier heating and channel length modulation have been taken into consideration for an accurate modeling of noise. The dependence of mobility fluctuations on the inversion carrier density has been incorporated. This has been validated by the experimental results. The noise behavior of p-channel device has been compared to that of a corresponding n-channel device. It has been observed that noise in p-channel device is comparatively higher due to higher number of oxide-trap density in it. Further, it has been noted that with the same trap density in both p-channel and n-channel device, the flicker noise in the p-channel device is lower than that of the corresponding n-channel device.     

Carrier-concentration dependence of velocity-field characteristics in ln0.53Ga0.47 as

The doping dependence of the velocity-field characteristic in InGaAs has been investigated by an analysis of measurements with transferred-electron devices. The electron peak velocity has been determined directly as a function of electron concentration and low-field mobility. The carrier-concentration dependence of the velocity-field characteristic has been deduced by comparing experimental and theoretical transient device behaviour. The experimental results support a theoretical approach for the velocity-field characteristic which has been proposed recently.     

A theoretical investigation of the rectangular microstrip antenna element

A theoretical treatment of the rectangular microstrip radiating element has been performed. The element has been modeled as a line resonator with radiation taking place at the open-circuited ends. This has been verified by using a liquid crystal visual detector. With the simplified model, the input impedance and the far fields have been calculated for different resonant modes. The interaction between the radiating ends will effect the input impedance, and this has been considered by defining a mutual conductance. Also, a mutual conductance between microstrip elements has been expressed in far-field quantities and plotted as a function of spacing along theE- andH- planes. The directivity of an isolated element has been calculated as the directivity of one radiating end times the contribution due to the array factor.     

Nonlinear theory of long-range-interaction resonant generators

A nonlinear self-consistent theory has been developed for resonant electronic generators of long-range interaction. The theory has been under development for devices whose electrodynamic system has a high Q-factor and a sufficiently rarefied spectrum. In accordance with the initial physical situation, the mathematical model under consideration has been obtained in the form of a system of differential equations, and an algorithm for its numerical solution has been proposed. The maximum amplitude of the generated oscillations in an open cavity with a Gaussian distribution of the field has been calculated analytically.     

The system modelling and circuit implementation from time–frequency domain signal specifications

The system modelling and the circuit implementation of the nonlinear circuits using the wavelet domain techniques has been accomplished in this study. When the time–frequency domain specifications have been given as the wavelet ridges, the signal with the given ridges has been synthesized. Then, the dynamical wavelet network has been trained for the synthesized signal. The circuit of the wavelet network has been designed and simulated.     

H表达的ECLD双稳环环宽的研究

采用H参量简化模型研究光栅调谐外腔半导体激光器的双稳特性,导出以H参量表达的双稳环环宽解析式,给出了其适用范围,得到剩余反射率减小时导致双稳环消失的临界值,然后数值模拟了光栅反射率、谱线展宽因子、H参量、剩余反射率对载流子密度与频率关系曲线的影响,从中发现了剩余反射率增大时也存在双稳环环宽为零的情况,数值计算了剩余反射率极限值,并指出了环宽极大值的位置。     

Single pole compact narrow band pass filter using periodic ground defects

In this paper a compact narrow band pass filter has been designed. An H-shape section of microstrip is used to get the smaller band width. The parallel lines are connected to the H section. The periodic slots are made on the ground plane of the microstrip. These defects cause the circuit more compact. The filter has been designed for center frequency 4 GHz and fractional band width 3%. The design methodology has been clearly explained. To verify the proposed technique, a filter has been fabricated and tested. Amoderate matching of the results between the measured and simulated results has been observed due to some imperfection in fabrication.     

Binary detection in presence of film grain noise and intersymbol interference

Detection of binary images in film grain noise with intersymbol interference (ISI) has been investigated. The film grain noise has been modelled as signal dependent additive noise in the density domain. The ISI is assumed to be caused only by its four predominant neighbours. Detection performance has been analysed using statistical decision theory. Probability of error curves have been obtained for two films namely fine grain roll film and microfilm. The effect of signal to noise ratio and aperture size has been examined and discussed.