Coupling through an Aperture Containing an Anisotropic Ferrite

Coupling through an aperture containing anisotropic ferrites is investigated theoretically by a simple extension of Bethe's hole coupling theory to include the dipole moment of the body in the aperture. The magnetic dipole moment of the ferrite body is ordinarily a vector but becomes a tensor upon the application of a field. This new theory is applicable to any situation where Bethe's small-hole coupling theory is valid. Experimental verification was quite satisfactory and was obtained on two Bethehole couplers: one with the waveguides parallel, and the other with the waveguides perpendicular.     

Integration of an SCR in an active clamp

This paper presents the integration of an SCR into a HV power clamp. For low currents the structure operates in “active clamp” mode and clamps the voltage to a value above the maximum operating voltage. After snapback the structure clamps the voltage to a low value as an SCR.     

Diffraction of an electromagnetic wave from an infinitely long slit in an infinite metallic sheet

The diffraction of anE-polarized and anH-polarized wave by an imperfectly conducting slit (on which impedance boundary conditions are imposed) in an infinite metallic plane is investigated. The two independent problems are solved by using integral transforms, the Wiener-Hopf technique and asymptotic approximations. It is found that the diffracted field consists of the sum of fields produced by the two edges of the planes formed by the slit and a field due to the interaction of the two edges.     

Equivalent currents for an aperture in an impedance surface

Expressions of equivalent magnetic and electric currents for an aperture in an impedance surface is derived in a self-consistent manner. Each equivalent current consists of the combination of the tangential electric and magnetic fields in the aperture, and is placed in front of the original aperture where the surface is extended to close the aperture. The result is particularly useful for problems involving apertures in an impedance ground plane     

Radiation from an aperture in an infinite conducting wedge

In this paper the problem of the far field radiation of an infinite aperture occupying one side of an infinite conducting wedge is solved. For uniform illuminations as well as for illuminations tapered to zero at the edges, it is shown that the radiated field can be effectively represented by line sources situated along the edge of the wedge. Also, for the special case of illuminations which taper to zero at the edges within a few wavelengths, it is shown that the shadow region radiation is proportional to the rate of taper.     

Realizing an Epitaxial Decorated Stanene with an Insulating Bandgap

The exploration of intriguing topological quantum physics in stanene has attracted enormous interest but is challenged by lacking desirable material samples. The successful fabrication of monolayer stanene on PbTe(111) films with low‐temperature molecular beam epitaxy and thorough characterizations of its atomic and electronic structures are reported here. In situ angle‐resolved photoemission spectroscopy together with first‐principles calculations identify two hole bands of p _xy orbital with a spin‐orbit coupling induced band splitting and meanwhile reveal an automatic passivation of p _z orbital of stanene. Importantly, material properties are tuned by substrate engineering, realizing a decorated stanene sample with truly insulating bulk on Sr‐doped PbTe. This finding paves a road for studies of stanene‐based topological quantum effects and electronics.     

位于任意形状导体上的天线输入阻抗分析

分析位于任意形状导体上天线的输入阻抗是一个复杂的电磁边值问题，这类问题一般很难得到解析解。在数值分析中，矩量法是一个非常有用的工具。线栅法曾被用来分析这类三维问题。但对于天线的近场特性，它存在一定的不足和困难。面元剖分可以克服线栅法的缺点。Ｒａｏ采用三角面元剖分方法，分析了位于导体上的天线特性。然而，在Ｒａｏ的数值模型中，他将结点区对边边界上的电流假设为零。为此，我们对Ｒａｏ的这一结点模型进行了修正，修正后的结果表明，理论与实验符合得较好     

Control of an electrical prosthesis with an SSVEP-based BCI

Brain-computer interfaces (BCIs) are systems that establish a direct connection between the human brain and a computer, thus providing an additional communication channel. They are used in a broad field of applications nowadays. One important issue is the control of neuroprosthetic devices for the restoration of the grasp function in spinal-cord-injured people. In this communication, an asynchronous (self-paced) four-class BCI based on steady-state visual evoked potentials (SSVEPs) was used to control a two-axes electrical hand prosthesis. During training, four healthy participants reached an online classification accuracy between 44% and 88%. Controlling the prosthetic hand asynchronously, the participants reached a performance of 75.5 to 217.5 s to copy a series of movements, whereas the fastest possible duration determined by the setup was 64 s. The number of false negative (FN) decisions varied from 0 to 10 (the maximal possible decisions were 34). It can be stated that the SSVEP-based BCI, operating in an asynchronous mode, is feasible for the control of neuroprosthetic devices with the flickering lights mounted on its surface.     

Clinical application of an active electrode using an operationalamplifier

An active electrode (d10 mm, t6 mm) is presented, that functions as an impedance transformer (an input impedance > 10 G omega, an output impedance < 1 omega) by means of which we can derive surface EMG without any skin preparation and paste. This electrode was compared with a conventional one, and it was ascertained that the electrode could be replaced with the conventional one, and, moreover, it was preferable because it required less preparation time, and was less affected by environmental noise.     

专用DSP提升数码相机音频编解码器性能

安捷伦科技公司为其93000 SOC系列推出Audio/Video 8模拟卡,这是半导体测试行业中第一个为真正的并行多站模拟测试提供8个独立单元的插卡.Agilent Audio/Video 8卡使消费品中使用的蜂窝基带和其它混合信号SOC/SIP的测试成本降低了20%,如手机、汽车音响系统、机顶盒、MP3播放机和电脑声卡.     

电偶极子在无限大各向异性媒质中的辐射场

分析电偶极子在无限大各向异性媒质中的辐射场，得出了近区场地级数表达式。分析计算了电偶极子平行天于地磁场时在无限大均匀各向异性电离层中的远区场。     

Analysis of an End Launcher for an X-Band Rectangular Waveguide

The analysis of an end-launcher type, coaxial-to-rectangular waveguide transition, exciting dominant TE/sub 01/ mode in X-band rectangular waveguide is presented. Expressions for the real and imaginary parts of the input impedance seen by the coaxial line are derived for the general case of an offset launcher using self-reaction of an assumed current over the loop. The dimensions of the combined electric and magnetic loops having low input VSWR in the coaxial line are determined. There is satisfactory agreement between theoretical and experimental results.     

Direct simulation of an iron-cored coil for an analogue computer

In the developement of automatic control using electrical machines and in studies of electrical-network stability, it is necessary to consider hysteresis and saturation on complete or partial loops of iron-cored windings. The present work describes a way to introduce a true magnetic loop given by a magnetic model with a Hall-effect device is in analogue-computer simulation. As an example, this device is applied to the process of self-excitation of a d.c. shunt generator     

Design of an Analogue VLSI Model of an Active Cochlea

A model of an active cochlea featuring a frequency selectivegain adaptation is proposed. The model is developed for analogueVLSI implementation and is based on the original analog electroniccochlea proposed by Lyon and Mead (1988) which consists ofa second-order lowpass filter cascade. At any position alongthe cochlea, the gain is locally controlled by the output levelat this position through the quality factor of the second-orderlowpass filter which best participates to this local gain. Inorder to achieve a 40dB compression with a limited local qualityfactor, the pseudoresonance of the cascade is used. A carefulanalysis of the functional model, supported by realistic computersimulations, shows the validity of the model by comparison withits biological counterpart. All the building blocks for an analogueVLSI implementation are proposed, taking into account the majortechnological limitations of a standard CMOS process.     

How to make networking an art...not an accident

Networking is more than a business buzzword. It's your vital connection to potential clients, new opportunities, business resources, and career support. Cultivating a circle of contacts makes your job a whole lot easier as well as a lot more fun and profitable. You need to know how to make contacts. Otherwise, your creativity, your career, and your professional growth will stagnate. So find out what's going on and who's doing what in your field. The social skills described in the following article may be the most neglected factors in your career     

Demonstration of an Integrated Buffer for an All-Optical Packet Router

We demonstrate an integrated optical buffer, fabricated in silica, with data storage up to 100 ns. The buffer consists of an array of waveguide delays between matched arrayed waveguide grating (AWG) routers and is designed for an all-optical packet router where buffering is required to resolve packet contention. By changing the incoming signal wavelength, the output port of the first AWG router is selected, thereby selecting a storage time in the buffer. All buffer channels have been demonstrated at 40 Gb/s with error-free operation and penalties of $sim$ 2–4 dB for bit-error rate $=1times 10^{-9}$.