最新刊期
卷 ， 期 4 ， 1981
- 摘要：In this paper, it is shown that a linear transformation exists between two kinds of guided modes in an inhomogeneous optical fiber waveguide with a parabolic-profile of the refrective index. Some characteristics of the transformation matrices are discussed.2|46|1更新时间：2025-12-08
- 摘要：A computation method used for doubly reentrant cylindrical cavity of klystron is developed in this paper. According to equivalent principle of field the cavity is divided into three regular regions. The field in each region is supported by proper surface magnetic current density on the common surface and can be expressed as integrals of Green functions.The magnetic fields of two neighbouring regions are then matched on the common surface to yield a set of integral equations. By use of Galerkin’s method these integral equations are transformed into a set of linear algebraic equations from which the eigenvalue, i. e. resonant frequency of the cavity, and magnetic current densities can be solved. And then another important parameter R/Q may be determined on the basis of the field distribution. Some computation results of cavities with typical dimensions are given and compared reasonably well with experimental data. It is shown that this method is superior to other numerical method （finite difference method or finite element method） in the following aspects: simplicity, higher accuracy, less inner stores, and less computing time.2|125|26更新时间：2025-12-08
- 摘要：Under the Wiener least mean square （LMS） criteria, the performance of an adaptive noise cancelling filter is considered. Using the solution of optimum transfer function in frequency domain, we prove the limit cancelling ability and system gain are proportional with 1/τ, where τ is the correlation radius between input noise. The elementary conditions that must be satisfied in application of noise cancelling are given.In time domain, a transverse filter can approximate the optimum linear system with arbitrary accuracy. The representation of their relation is given. The results given in this paper can be easily applied to adaptive beamforming systems.A method （which is based on the inverse matrix of cross-power density spectrum） for calculating the ability of adaptive beamforming system to reject planar interference is given. A block diagram of system simulation by computer and some experimental results are shown at the end of the paper.2|169|3更新时间：2025-12-08
- 摘要：In this paper, the author proposes a new protest for unbleached holograms on the silver halide medium, essentially consisted of phase type, though previously of amplitude type. This hologram has been acquired through practice by the author, and applied to the original hologram and also the replica for "the hologram micro-fiche storage systems with a large capacity". Both the original characteristics of the previous unbleached amplitude silver hologram and the efficiency of the similar bleached phase silver halide hologram are available in this new unbleached hologram. The 1st order diffraction efficiency measured of this new unbleached grating is about 20%, but the previous unbleached theoratical diffraction efficiency is 6.3% only. 10,000 alphabets or 3,500 Chinese characters or -1×105 bits can be stored and replicated in a small circle about 1mm in diameter. The reconstructed image is very clear and without speckle noise. These holograms show extremely good light stability.2|21|0更新时间：2025-12-08
- 摘要：In this paper, a method based on the triangular unequality is used to explain themaximum power transfer theorem in n-ports network. This method of proof is not only rigid and terse, it can also determine directly the condition of the maximum power transfer and the supremum of the available power drawn by the terminated load. Moreover, with this method, it is not necessary to decide whether the extreme value is of local or global optimum nor is it necessary to determine whether the objective function is convex or non-convex prior to finding the extreme value. However, these are unavoidable requirements if the usual varia-tional method is employed.The general formula of the optimum load impedance is derived in a detailed manner when internal impedance of network, Hermite matrix Zs+Zs*, is positive definite. It would appear that there are infinite numbers of the optimal load impedance matrices satisfying the maximum power transfer condition, where all solutions except one are nontrivial. The set composed of all these solutions constitutes a n2-n dimensional linear submanifold in complex space Cn2 . It is to be noted that trivial solution may evade influence of source vectors, and as is well known, this is an important characteristic in its implementation, but it requires to achieve match between corresponding components of the mutual impedance respectively. In contrast, those nontrivial solution may avoid such a difficult task of matching between corresponding components of the mutual impedance, but the influence of source vectors cannot be avoided.This paper applies, some mathematical accomplishments based on intuitive conception of projective geometry and the theory of generalized inverses, which are good at dealing with the problem considered impossible to solve in the sense of a solution of a nonsingular problem, i. e. the so-called "ill-posed" linear problem. Obviously, the optimal current will be solved if internal impedance of network Zs+Zs* is positive semidefinite. Hence, the optimal load impedance matrices may be found provided that results obtained in the positive definite condition are utilized directly. Finally, it also shows by the operation of cardinal numbers that the numbers of optimal load impedances make no difference between the positive definite and positive semidefinite conditions.2|21|1更新时间：2025-12-08
- 摘要：<正> 南京固体器件研究所采用In/PCI3/H2系统气相外延生长的n+-n-n+InP材料,采用适用于InP的Au-Ge-Ni合金欧姆接触、化学腐蚀减薄衬底和光照刻蚀台面等工艺,制作了台式镀金热沉结构的毫米波段连续波体效应振荡二极管（见照片）。该器件有源区的掺杂浓度为7.35×1015cm-3,厚度为2.85μm;台面直径约70μm,台面高度为15μm;管壳系无边缘同轴封装。用V波段同轴波导腔测试微波性能,得到的初2|36|0更新时间：2025-12-08
- 摘要：At present, it is necessary to use the frequency reuse system with dual circular polarization in the Intelsat-V.This system needs not only the antennas with very high polarization purity, but also the polarization corrector to overcome the depolarization effect due to rain.In this paper, three kinds of polarization correctors are analyzed with the complex vector method and the equations for computing their characteristics have been obtained.All the equations for the best axial ratio, residual depolarization disturbance, error signal and the control signal are expressed here directly with the angular position errors, phase errors and amplitude errors of the phasers. Thus the regret expressed by DiFonzo may be avoided with these equations and simple direct error feed back is possible.With the equations given in this paper, it is possible to predict the performances of the polarization corrector, such as the best axial ratio and residual depolarization disturbance or to determine the specifications of the components for the corrector, such as the phaser’s phase errors, amplitude errors and angular position errors.According to the polarization situation of the coming wave, the best work region of the polarization corrector can be selected for improving the best axial ratio and decreasing the residual depolarization disturbance.2|62|2更新时间：2025-12-08
- 摘要：By reviewing author’s study on doubly curved shaped beam reflector antennatheory,it is suggested that by utilizing common elliptic shaped strips reflectors can be constructed, thus generalizing synthetic theory. Formulae have been derived for principal and cross polarization components in far field as well as for antenna in the far field with offset feed or off-axis feed. In particular, formulae for far field patterns in the main radiating region have been given.2|118|19更新时间：2025-12-08
- 摘要：<正> 永川光电研究所去年研制成功了一种高辐射率的GaAs-AlGaAs双异质结侧面发光二极管,它采用了SiO2掩蔽的条形电极结构。在掺硅的N型GaAs单晶的<100>面上相继外延生长出N型AlxGal-xAs,P型AlyGal-yAs,P型AlxGal-xAs和P型GaAs四层外延层,所构成的双异质结来实现对光和载流子的纵向限制;在P型面上进行闭管Zn扩散,然后溅射出厚为0.4μm的SiO2层,光刻出宽度为60μm的电极引线条,这样来实现对光和载流子的横向限制。有源区掺硅的厚度为0.3μm左右。解理出的管芯的宽度对2|31|0更新时间：2025-12-08
- 摘要：: Formulas for calculating the interference noise power in base band and interference reduction factor of frequency modulated TV system interfered by RF signals are derived. The RF signal may be a FM telephone signal, a FM television signal or an impulse radar signal. Some useful conclusions based on theoretical analysis are also presented. The approximation used in calculating the interference reduction factor is discussed, and then some typical interference objectives including RF protection ratio and base band signal-to-noise ratio are calculated in detail.In the formulas derived, almost all important variables which affect the value of the interference reduction factor have been taken into account. These variables are carrier frequency off-set value, pre-emphasis factor, weighting factor, video spectral distribution and nominal peak to peak frequency deviation. If neglecting all the variables except nominal peak to peak frequency deviation, the derived formula may be reduced very closely to the approximate expression of results from objective measurements given by CGIR Rep. 634-1. This shows that the formulas given in this paper are a theoretical development to that local experimental knowledge. It is now possible to compute the interference into FM TV systems and the computation is as reliable as that in telephony. It is believed that the derived formulas will be usefulto interference analysis and co-ordination.2|13|3更新时间：2025-12-08
- 摘要：<正> 中国电子学会化学与物理电源学会于4月15日至21日在重庆市举行了1981年年会,来自全国124个单位的239名代表参加了年会活动。代表们就化学与物理电源的基础理论、生产工艺及新产品研制等方面,展开了充分的学术讨论和经验交流,并对如何加强我国电池工业的科学管理作了探讨。会议内容丰富、气氛活跃,达到了预期的目的。2|11|0更新时间：2025-12-08
- 摘要：In this paper we have analysed the working characteristics of the pulse-counter detector of small sliding window, and proved that the process of detector state change is a Markov Chain. We have obtained two calculating formulae based on the strict definitions of the detection probability and false-alarm probability of the detector. The two formulae, which we have not read about hitherto, are applicable to various kinds of pulse-counter detectors of small sliding window.2|170|2更新时间：2025-12-08
- 摘要：The main problem in developing microprogrammable controlled high speed lest ipattern generator is that the pattern generating speed is limited by its instruction memory speed. Unfortunately, the speed of the memory which we adopt to build this instruction memory is never faster than that of the memory being developed. Therefore, the requirement on the pattern generator in testing high speed memories under development can never be met.We have designed a new instruction memory with an access time of only one AND-OR gate delay. It is suitable for the test pattern generator. Based on this principle, we have successfully developed our own microprogrammable controlled test pattern generator.This article describes the construction of two commercial semiconductor memory tester （Model BJ-1, Model QL-13）. It is followed by a brief discussion on a new pattern generator structure, namely, double handling construction. It seems that more benefits can be obtained from this instruction memory.2|24|0更新时间：2025-12-08
- 摘要：In this paper the fan beam reconstruction model （convolution-back projection） and its computation formulae are firstly reviewed. But the speed of computation is rather low, because these formulae are so complex that the quantity of computation is too large. In order to increase the speed of computation a fast algorithm has been developed. Under the same subjective and objective image fidelity the computational speed of the new algorithm has been increased by a factor of two in comparison with that of the conventional algorithm. This algorithm has been used in the reconstruction of some simple practical models. The result of the computation shows that this algorithm can be easily realized by hardware, because only one function （SIN） is used rather than many functions （TAN, ARCTAN and SQR etc.） involved. The algorithm can also be used in the x-ray computerized-tomography system and acoustic non-destructive detectors.2|27|1更新时间：2025-12-08
- 摘要：<正> 1981年6月1日至6日,中国电子学会微波学会在桂林市成功地召开了第三届学术年会。与这个会议同时并联合召开的还有:中国光学学会集成光学学术交流会,四机部激光情报网光纤通信专业组技术交流会以及四机部仪器测量情报网工作会议。 大会由中国电子学会微波学会副主任委员鲍家善教授主持,主任委员黄宏嘉教授介绍了会议筹备经过并向大会作了关于微波技术、光纤通信以及光路集成等国内外发展情况的学术报告。出席这次大会的有来自全2|15|0更新时间：2025-12-08
- 摘要：: In this paper, the potential and current patterns in the thin-film have been analyzed with the theory of 2-dimensional electric field. The expressions derived for attenuation, input and output characteristic impedance of attenuators with certain network patterns will prove to be of benefit for the design of thin-film attenuators. The dissipation power has also been discussed.2|117|2更新时间：2025-12-08
- 摘要：<正> 【本刊讯】今年4月28日,中国电子学会在北京新侨饭店举行的第六次常务理事会,研究了组织并召开本学会第一届会员代表大会及举办第三届学术年会的有关事宜,认为在1982年同时召开这两个大会将是合适的。会上决定成立第一届会员代表大会筹备委员会,并推举学会副理事长兼秘书长孙俊人同志为主任委员,2|9|0更新时间：2025-12-08
- 摘要：In this paper the research results of magnetostatic delay line with longitudinally magnetized nonellipsoidal YIG crystal are given. The multiple round trip echoes are observed especially with short delay time. The echoes are successfully suppressed by changing the boundary condition of the sample. At S-band useful delay time controlled magnetically ranges from 0 to 1μs. The untuned insertion loss at 2GHz and 4GHz is less than 26dB when delay time is about 1μs. But for the case of the echoes being suppressed the insertion loss is increased to some extent.2|26|2更新时间：2025-12-08
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