双旋Y切石英振子模式交替性的分析与研讨

本文通过描述固体中弹性声波的christoffel(克里斯托费尔)方程,分析了在石英晶体中,由于其对称性的限制而显示出各向异性的切角范围0≤φ_3≤60°,0≤φ_1≤90°(或0≤φ_3≤30°,-90°≤φ_1≤90°)内,双旋Y切石英振子T模(厚度模)的特性。其中着重分析了30°≤φ_3≤60°,24°≤φ_1≤32°(或0≤φ_3≤30°,-32°≤φ_1≤-24°)这一区域内的T模特性,证实了美国36届频率控制年会报道的“当φ_3在0～10°之间时,存在着b、c摸的交替点”的论述。并得出了两个特定的交替点切角(φ_3°,φ_1°),这在我们所见到的资料中尚未见报道。这些结果对掌握振模的本质,提高石英振子的性能等方面是有实际意义的。     

双旋Y切石英振子“T”模分析及SC切双模同时振荡的研究

本文推导了石英晶体基本物理参数的双旋变换关系,并利用克里斯托费尔方程,对其厚度模式的a、b、c三个模作了分析。文中也论证了SC切中b、c模的正交性,并用一块SC切晶体同时激励了b、c模振荡,给出了双模振荡器的测试结果,它表明利用b模频率信息来对C模实行最佳温度补偿是可能的。     

旋转Y切石英谐振器的幅频非线性效应分析与研究

通过对幅频非线性效应的分析,详细地推导了旋转Y切石英谐振器的纯厚度切变模的幅频公式,并计算了幅频效应曲线.分析结果表明,通过选择切型可获得尽量小的幅频系数D,以及通过控制激励幅度来减小幅频影响的途径,从中也发现了石英谐振器的Q值(品质因素)对幅频曲线有影响.     

BT切石英谐振器频率温度特性的估算

本文介绍了BT切石英谐振器的频率温度特性估算。结合实验数据，求出最佳切角及合理的切角误差。     

平面反射阵列天线相移特性分析

本文中采用十字交叉振子为单元分析其移相特性.利用Floquet模展开分析了任意平面波照射下的交叉振子阵列的场分布,计算出其反射系数的相位变化情况.通过数值仿真,分别给出了在不同介质、介质厚度以及入射角度下,详细对比了相位对于振子长度的变化曲线,有助于反射阵列大线的精确设计.     

铌酸锂和钽酸锂的频率温度系数研究

铌酸锂(LN)和钽酸锂(LT)具有弹光及电光效应,可用于压电振子、压电换能器及压电驱动器,而这些器件受切角对频率温度系数影响大.该文主要研究了一级频率温度系数分别随绕x轴和x轴旋转切角θ1和θ3的变化,且画出了各个切型下,一级频率温度系数随切角变化的曲线图,从而确定了LT晶体的零温度切角和LN的近似零温度切角,对由LT和LN制成的晶体器件的切角选择具有指导意义.     

DIC光纤的内包层参数研究

大沉积厚度、浅凹陷内包层(DIC)光纤广泛地应用于单模长距离陆地通信和海底通信。本文研究这种结构光纤的内包层参数(b/a,δ)对模截止特性和漏模损耗特性的影响,并对这些影响给出了相应的实验证明。     

双包层手征光纤的色散特性

在对双包层手征光纤(W型)进行解析求解的基础上，用数值计算方法研究了纤芯和内外包层的手征参数和内包层厚度对模式色散特性的影响，给出了双包层手征光纤中基模的归一化传播常数b、群延迟d(Vb)／dV和波导色散Vd2(V6)／dV2随纤芯和内外包层的手征参数和内包层厚度的变化关系曲线。结果表明在双包层光纤的纤芯和内外包层中引入手征，可以极大地改变光纤中基模的色散特性，特别是内包层厚度不同时，色散特性也极为不同．     

小型SC切恒温晶体振荡器的研制

论述了高稳定度、小体积恒温晶体振荡器 (OCXO)的热学结构设计和测温控温方法。采用 SC切三次泛音石英晶体谐振器作为振荡元件 ,利用 DS1 82 0作为温度探测器 ,以 PIC1 6 F84作为微控制器 ,通过 PID算法和脉宽调制技术 (PWM)对振荡电路进行温度调节与控制 ,以达到恒温目的。研制出体积为 40 mm× 40 mm× 1 4mm、频温特性达 1 0 -8的高稳恒温晶体振荡器     

AT切石英谐振器频率温度系数的研究

分析了AT切石英谐振器的频率温度系数与晶体弹性模量、密度、尺寸及环境因素间的关系。引进了1~3阶频率温度系数的修正系数,解释了频率温度系数的变化问题。结果表明,对切角及环境因素进行控制,可使石英晶体谐振器的频率–温度特性满足工程的需要。     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.