Table of Content

30 June 1983, Volume 1 Issue 2

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Articles

THIRTY YEARS OF MICROWAVES IN CHINA

HUANG HUNGCHIA

1983, 1(2):  95-106. 

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This is an invited paper which the author presented in June 1982 at the IEEE MTT-S International Symposium on Microwaves, with "30 Years of Microwaves" as its theme. For the benefit of a large circle of Chinese readers interested in this subject, it is considered as appropriate to publish a Chinese version of the paper of similar but not identical content.

GROWTH OF HIGH PURITY InAs CRYSTALS AND A DISCUSSION ON THE RESIDUAL DONORS I.Relationship Between the Concentrations of Shallow Donor and Total Acceptor and a Speculation About the Nature of Residual Donor in InAs

ZOU YUANXI

1983, 1(2):  107-110. 

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A correlation between the calculated concentrations of shallow donor (N_D) and total acceptor (N_A) in InAs is deducod on the basis of the published data. It is shown that the data for bulk, VPE and LPE materials can be expressed by a single N_D versus N_A curve. This result leads to a reasonable inference that the total concentration of impurities Si, Cu, Na (K)， S (Se, Te) and perhaps also G, could be responsible for the residual donor concentration in InAs.

OPTIMAL REDUCED MODEL WITHOUT STEADY-STATE OUTPUT ERROR SUBJECT TO POLYNOMIAL INPUTS

ZHANG ZHONGJUN, BAI ERWEI, YANG PEIQING

1983, 1(2):  111-120. 

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A new reduced model for high-order systems is investigated in this paper.
It is shown that such model is optimal for matched outputs in the sense of integral-square-error criterion subject to an Impulse input and also without steady-state output error for polynomial inputs. The necessary condition of the problem and its algorithm are derired. An example for a SIMO system is calculated and compared with that obtained by Wilson's method. Extension, of reduced model to MIMO systems is formulated.

CHARACTERISTIC MATRIX OF PERIODIC POTENTIAL IN ONE DIMENSION AND ITS APPLICATIONS

SHEN HONGEN, FANG JUNXIN

1983, 1(2):  121-134. 

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The behaviour of electrons in a crystal can be described by Sohrodinger's equation for a periodic potential. Up to now, the transfer matrix technique remains one of the best available to solve problems in one dimension. In this paper, a new matrix method called "the characteristic matrix of periodic potential" is introduced. The traditional transfer matrix connects two amplitudes of plane waves or Bloch waves. Instead, the characteristic matrix simply connecting wave functions and their derivates, makes the evaluation of the elements of characteristic matrix simpler than that of transfer matrix, and makes it more suitable for solving the energy values for complicated potentials in one dimension, especially the periodic potentials.

COMPUTING FIN-LINE DISPERSION CHARACTERISTICS WITH FINITE ELEMENT METHOD

XU SHANJIA

1983, 1(2):  135-142. 

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In this paper, starting from solving eigenvalue problem of wavegurdes filled with inhomogeneous dielectrics, fin-line dispersion is calculated by means of the finite element method. As a result of considering the effect caused by the fin thickness on dispersion, the results obtained by other methods may be modified. The dispersion characteristics obtained by unified program for fin-line, ridged waveguide and slab-loaded waveguide are in good agreement with results obtained by other methods. Practical measurements of dispersion shaw an agreement between computed results with fin thickness to be considered and experiments, thus justify the discribed method.

X-RAY STUDY AND ESTIMATION OF ACOUSTO-OPTIC PROPERTIES OF THE COMPOUNDS IN PbO-Nb₂O₅ SYSTEM

XU YUEYING, JIN XIAOYIN, TAN HAORAN

1983, 1(2):  143-152. 

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X-ray study, density measurement and estimation of aoousto-optic properties of the compounds in PbO-Nb₂O₅ system were carried out. Existence of the six PbO-NbaOs compounds reported by Roth was confirmed by X-ray analysis. Cell parameters and powder diffraction data were accurately measured for the compounds P₃N and P₅N₂. It was found that in the mixture of PbO and Nb₂O₅ with a composition of P₅N₂ heated at 900~1150℃ there exists P₃N as an intormediate phase. In this system the compounds P₃N, P₅N₂, P₂N and P₃N₂ with high PbO contents all possess large values of acousto-optio figures of merit and thus are promising new aoousto-optic materials.

FINITE ELEMENT APPROXIMATION OF THREE DIMENSIONAL FLOW IN TURBOMACHINES

LI KAITAI, HUANG AIXIANG

1983, 1(2):  153-164. 

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In this paper, by applying the tensor analysis and semigeodesio coordinate system, we have established a partial differential equation and conditions satisfied by the stream function on any stream surface of three dimensional flow in turbomachines. We have also provided computational examples by use of finite element method, and the error estimate of Galerkin's finite element approximation solution which depends on Mach number.
In addition, we have drawn the conclusion that the transonic equation for three dimensional compressible flow in the turbomachines is equivalent to an optimal control problem of a linearly distributed parameter system. This problem can be disoretized by the finite element method and solved by a conjugate gradient algorithm. A new class of method for solving the transonic equation is particularly well adapted to problems with complicated three dimensional geometries and shocks, and at the same time it can be used to improve the precision of approximation solution.

OPTIMIZATION OF OPERATING PARAMETERS OF GYROMONOTRON WITH A SLOWLY VARYING MAGNETIC FIELD

ZHU MIN, WU HONGSHI

1983, 1(2):  165-174. 

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An optimization program for the operating parameters and efficiency of gyrom-onotron based on the optimum control theory has been discussed in this paper. In this program we employ the orbit theory of gyromonotron and adopt a slowly varying static magnetic field to enhance the interaction efficiency. An integrated optimum control problem comprising the state equations, the conjugate equations, the objective functional and the functional gradient is worked on in detail in a slowly time-varying coordinate system. The above optimization problem is numerically solved using Goldfarb's method (BQFS method) for fixed parameters V₀ (beam voltage) and a (ratio of initial transverse velocity to parallel velocity) to obtain the optimum operation parameters A, N_λ, μ, b₁, b₂, and optimum interaction efficiency η_e. Then the product of QI can be calculated. A large number of optimized data which can be used in design of gyromonotron are provided and some remarks on this theoretical analysis are given.

RADIATION CURING OF ACRYLATE COATING THE EFFECT OF OLIGOMER STRUCTURE AND MOLECULAR WEIGHT ON RADIATION CURING RATE

ZHAO XIANGZHEN, MA ZUETEH, DONG LIANGCHANG

1983, 1(2):  175-184. 

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Nine different kinds of polyether aorylate isocyanate oligomers were synthesized. The effect of their structures and molecular weights on radiation curing rate, curing dose and final gel content were investigated. Following results were obtained.

DESIGN OF MICROWAVE APPARATUS FOR ACUPUNCTURE TREATMENT AND MEASUREMENTS OF MICROWAVE REFLECTION POWER FROM THE ANIMAL MEDIUM

HUANG ZHIXUN

1983, 1(2):  185-188. 

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A microwave apparatus for acupuncture treatment is described. The apparatus described is based on a 50Ω,1000 MHz transistor oscillator. The design considerations and performance data of the oscillator are presented. This oscillator has 1.5 watts output, 25% transfer efficiency, and 10% power stability. Nominal input voltage is -24v dc.
In addition, we have made a thorough investigation of the microwave reflection power from the surface of the animal medium according to the rabbit experiments. We have used the slotted line for measuring voltage standing-wave ratios, but reflection power can be measured even faster, by use of a circulator device.