摘要:The network extension theory and its applications for analysis of circuits are introduced. Developed just in recent years, the theory deals chiefly with the properties of networks when some changes in their construction take place, providing a new approach for circuit analysis. The approach is efficient especially for the treatment of modifications and connections of networks and for the generation of symbolic network functions of large scale networks. Some practical techniques are discussed in detail. Several examples of the approach are given to show its efficiency and simplicity.
摘要:By using the method of equivalent magnetic current together with Bethe’s theory of small aperture coupling, a pratical method is presented to solve small aperture coupling between dissimilar regions. Simple generalized equivalent networks are given for several typical examples.By connecting any two of them, coupling between two corresponding regions can be formulated.
摘要:This paper analysis the conjugate match circuit of the. two-port network and n-port generalized reflectometer by means of the pair of conjugate match network.The appropriate measurement methods have been established on the analysis results. The concept of the generalized reflection coefficient can be used to measure the intrinsic parameters and the circuit parameters of the one-port and two-port elements.
摘要:A physical model and related formulas for the calculation of small-signal gain and phase shift in a severed injected-beam crossed-field amplifier are presented in this paper. The analysis is based on the linear theory of thin beam CFA with the space charge effect included. In the analysis the space charge effect as well as the circuit loss and the velocity difference between electrons and undisturbed waves are considered."Sever Drop"and "Sever Phase Shift" are introduced in formulas to represent the effect of the sever.The"Sever Drop"can be of a negative value due to the Diocotron effect in the sever. The influence of sever location on the gain is also analyzed based on a zero-length sever model.
摘要:On the basis of the six-valued logic system, an H-algorithm is suggested for the test generation of asynchronous sequential circuits. A comparison between the H-algorithm and the nine-valued algorithm is made. It is shown that the H-algorithm guarantees the validity of the obtained test sequence and keeps the sequence free from race condition.
摘要:A new conception of Decision Feedback-feedforward Equalizer (DFFE) is proposed. Two types of optimum receivers derived under MMSE criterion with and without ZF constraint are described, and their tap adjustment algorithms are also given. An upper bound on the error probability in DFFE with ZF constraint is derived. It is proved that either with or without ZF constraint, the error probability in DFFE is lower than in DFE. Computer simulation shows that the adaptive scheme is feasible.For simple implementation, the preequalizer may be omitted in DFFE. Convergence is then independent of channel parameters, and the number of its taps is reduced to a minimum.
摘要:Both nonreciprocal birefringent effect and variable polarization effect of microwave ferrite in the symmetrical four-pole magnetized field are discussed in the light of coupling-wave theory. A concept of the tensor permeability in the multicenter-magnetized inho-mogeneous magnetized systems in a latching state is proposed. Two methods of variable polarization are discussed, and some formulae for wave-mode differential phase, nonreciprocal phase and variable polarization coefficient are deduced. The experimental results are in good agreement with the theoretical calculations.
摘要:Based on the generalized inverse matrix, a group of definitions are given for general transmission matrix. It is pointed out that the general transmission matrix has itsadvantages and limitations in analyzing the cascade of conventional multiport--non-2m-port--networks.
摘要:The factors which may have influence upon the formation of swirl defects in P-type <100>, <111> CZ Si crystal were studied. It was found that the cooling rate of the grown crystals is critical for the formation of swirl defects. The oxygen content in the range of 0.5-1.7×10(18)/cm3, and the carbon content in the range of 0.2-1.9×10(17)cm3 have no obvious effect on the formation of swirl defects. Though serious remelt had been observed when the distance between crystal axis and crucible axis became 8mm, yet it is still possible to obtain swirlfree crystals by adopting proper cooling rate.
摘要:The decision-making method for product development based on statistico-analysis of historical data is discussed. It consists of identifying the main factors influencing the results of product development, calculating the probabilities of those influences on product development and by way of weighted assessment, deriving the minimum development decision value for the genus of products and determining the actual decision value of the product in question belonging to the genus. If the value of the product under consideration is found to be greater than the minimum value required for its genus, the product can be developed. For products without historical data, this paper gives the minimum decision values based on normal distribution law and practical experience. This method has proved very useful in the development of consumer electronic products.
摘要:This paper reviews the evolution of programming notions, gives a systematic and comprehensive description of basic concepts, principles and techniques of program transformations, and puts forward some suggestions for the implementation of a program trans-ormation system.
Zou Shi-chang, Wang Wei-yuan, Lin Cheng-lu, Xia Guan-qun
Issue 1, Pages: 104-106(1983)
摘要:Backside irradiation through the substrate with a CW CO2 laser has been used to produce Au-Ge-Ni ohmic contacts on n-GaAs with different doping concentrations(6×10(14)-7×10(17)cm-3).The laser alloyed contacts show better ohmic behavior and a contact resistance lower than that of furnace alloyed contacts by approximately an order of magnitude for low bulk concentrations(5×10(18)cm-3).The formation of a Ge-enri-ched n-type GaAs layer after laser alloying, as shown by the results of AES analysis, is helpful to improve the interface properties of the contacts.
摘要:It is usually observed that the conditions of self-excitation of LC sinusoidal oscillator are: (l)arg KF=±2nπ, (2)k =|KF|=(βM/rbcCR)≥1. Tnis paper points out that the above conclusion is not totally right.