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1993 Vol. 15, No. 4
Display Method:
1993, 15(4): 337-342.
Abstract:
Analysis approach and formulas for the transmission properties of uniform multiconductor interconnecting buses in high s peed integrated circuits are presented in this article. And further, by using a network approach, a tapered bus system can be analysed as a set of cascaded uniform buses with slightly different strip widths. Obtained results are in good agreement with the experimental data.
Analysis approach and formulas for the transmission properties of uniform multiconductor interconnecting buses in high s peed integrated circuits are presented in this article. And further, by using a network approach, a tapered bus system can be analysed as a set of cascaded uniform buses with slightly different strip widths. Obtained results are in good agreement with the experimental data.
1993, 15(4): 343-350.
Abstract:
The time-domain radiation characteristic of a three V-dipole array has been studied by direct time-domain method. Some valuable results are obtained.
The time-domain radiation characteristic of a three V-dipole array has been studied by direct time-domain method. Some valuable results are obtained.
1993, 15(4): 351-358.
Abstract:
The extraordinary waves of the ferrite medium are decomposed into TE and TM modes, through the Fourier transformation and a coordinate rotaion of Maxwell s equations. The wave admittances of TE and TM modes is neglected, the finline with magnetized fer-used and the coupling between TE and TM modes is neglected, the finline with magnetized fexrite substrate can equally he represented by a network. Comparing this approach with T. Itch s spectral domain immittance approach, the ideal transformers are used in the network. Finally, the forward and backward propagation constants for the unilateral finline loaded with magnetized ferrite have been calculated numerically. Numerical results agree weit with that given by Geshiro and Itoh.(1987).
The extraordinary waves of the ferrite medium are decomposed into TE and TM modes, through the Fourier transformation and a coordinate rotaion of Maxwell s equations. The wave admittances of TE and TM modes is neglected, the finline with magnetized fer-used and the coupling between TE and TM modes is neglected, the finline with magnetized fexrite substrate can equally he represented by a network. Comparing this approach with T. Itch s spectral domain immittance approach, the ideal transformers are used in the network. Finally, the forward and backward propagation constants for the unilateral finline loaded with magnetized ferrite have been calculated numerically. Numerical results agree weit with that given by Geshiro and Itoh.(1987).
1993, 15(4): 359-366.
Abstract:
The backscattering of light wave from arbitrary convex dielectric objects wich rough surface is investigated and the formulas for calculating the backscattering cross-section of both coherent and incoherent fields are obtained. In the infrared wave-band, the influence of the geometry, permittivity and statistic characteristics of the rough surface on LRCS is analysed, making use of rough spheres and ellipsoids as examples.
The backscattering of light wave from arbitrary convex dielectric objects wich rough surface is investigated and the formulas for calculating the backscattering cross-section of both coherent and incoherent fields are obtained. In the infrared wave-band, the influence of the geometry, permittivity and statistic characteristics of the rough surface on LRCS is analysed, making use of rough spheres and ellipsoids as examples.
1993, 15(4): 367-374.
Abstract:
Ion-channel laser (ICL) is a new form of free electron laser which can produce tunable-coherent radiation with frequencies ranging from microwave to soft X rays. In this paper, the amplification mechanism of ICL in low gain regime is investigated. Using the Madey theory, the gain formula of ICL is derived. Two different bunching mechanism of the electrons in ICL are discussed through the bunching parameter Bi. The output frequency of ICL is obtained from the resonance condition, and the comparison is carrying out among ICL Cyclotron Auto Resonance Maser (CARM) and conventional Free Electron Laser (FEL).
Ion-channel laser (ICL) is a new form of free electron laser which can produce tunable-coherent radiation with frequencies ranging from microwave to soft X rays. In this paper, the amplification mechanism of ICL in low gain regime is investigated. Using the Madey theory, the gain formula of ICL is derived. Two different bunching mechanism of the electrons in ICL are discussed through the bunching parameter Bi. The output frequency of ICL is obtained from the resonance condition, and the comparison is carrying out among ICL Cyclotron Auto Resonance Maser (CARM) and conventional Free Electron Laser (FEL).
1993, 15(4): 375-381.
Abstract:
In recent years, adaptive clutter suppression for airborne early warning (AEW) radars have attracted considerable attention. A necessary condition for efficient clutter suppression is that the number of adaptive degree of freedom (DOF) is greater than the number of clutter DOF. This paper analyzes DOF of clutter for phased array AEW radars. The new results obtained are helpful to design a adaptive , system for clutter suppression.
In recent years, adaptive clutter suppression for airborne early warning (AEW) radars have attracted considerable attention. A necessary condition for efficient clutter suppression is that the number of adaptive degree of freedom (DOF) is greater than the number of clutter DOF. This paper analyzes DOF of clutter for phased array AEW radars. The new results obtained are helpful to design a adaptive , system for clutter suppression.
1993, 15(4): 382-387.
Abstract:
A new improved parameterization means of instantaneous signal is proposed. Its applications in the field of nuclear ex plosion detection are presented. The discus-sion will centre on the signal modelling and the algorithm of extracting signal parameter. Finally, some typical instances which apply to the field of nuclear explosion recognition and itscomputer simulations are given.
A new improved parameterization means of instantaneous signal is proposed. Its applications in the field of nuclear ex plosion detection are presented. The discus-sion will centre on the signal modelling and the algorithm of extracting signal parameter. Finally, some typical instances which apply to the field of nuclear explosion recognition and itscomputer simulations are given.
1993, 15(4): 388-395.
Abstract:
Based on the influence of circuit element tolerances to the k-fault diagnosis, a method of fault diagnosis is presented which is called as minimum tolerance estimation algorithm and has clear physical meaning. Using this method, an effective estimation of the equivzlent fault sources can be obtained with less computing time. It is especially worthwhile to point out that a self-adaptive sub-optimal algorithm, which comes from the above method, requires even less computing-labor and is particularly suitable for more complicated circuits as well as real-time fault location.
Based on the influence of circuit element tolerances to the k-fault diagnosis, a method of fault diagnosis is presented which is called as minimum tolerance estimation algorithm and has clear physical meaning. Using this method, an effective estimation of the equivzlent fault sources can be obtained with less computing time. It is especially worthwhile to point out that a self-adaptive sub-optimal algorithm, which comes from the above method, requires even less computing-labor and is particularly suitable for more complicated circuits as well as real-time fault location.
1993, 15(4): 396-403.
Abstract:
The problem of realization of two-port networks terminating with load is discussed. The mathematical model of solving parameters of a network is established. The software of computing parameter of network is given. It is convenient for the practical app tication.
The problem of realization of two-port networks terminating with load is discussed. The mathematical model of solving parameters of a network is established. The software of computing parameter of network is given. It is convenient for the practical app tication.
1993, 15(4): 404-409.
Abstract:
The concepts of k-order modified double-graphs and k-order modified matrices are introduced. By using them two new expressions of graph determinant C(Y) and k-order cofactor Y(ij)are deduced. Then the modified double-graph method is presented for finding symbolic k-order cofactors. By applying it a multi-layer expansion of Y(ij) can be found directly and efficiently (having no special sign evaluation poblem), and it produces no cancellation terms. Hence it is superior to the previous methods.
The concepts of k-order modified double-graphs and k-order modified matrices are introduced. By using them two new expressions of graph determinant C(Y) and k-order cofactor Y(ij)are deduced. Then the modified double-graph method is presented for finding symbolic k-order cofactors. By applying it a multi-layer expansion of Y(ij) can be found directly and efficiently (having no special sign evaluation poblem), and it produces no cancellation terms. Hence it is superior to the previous methods.
1993, 15(4): 410-415.
Abstract:
A effective multirate preprocessing technique for microwave imaging is presented. This technique has the advantages of largely compressing the original collected spectral data and reducing computational complexity of some imaging alogrithms. Also, the preprocessed spectral data is suitable for off-line superresolution imaging processing.
A effective multirate preprocessing technique for microwave imaging is presented. This technique has the advantages of largely compressing the original collected spectral data and reducing computational complexity of some imaging alogrithms. Also, the preprocessed spectral data is suitable for off-line superresolution imaging processing.
1993, 15(4): 416-420.
Abstract:
An ASM one-zero-hot design method of using ternary flip-flops with binary construction as storage cells is presented in this paper.
An ASM one-zero-hot design method of using ternary flip-flops with binary construction as storage cells is presented in this paper.
1993, 15(4): 421-424.
Abstract:
The method and system for measuring parametros of fL and of 1/f noise in BJT are presented. Finally, the examples are given.
The method and system for measuring parametros of fL and of 1/f noise in BJT are presented. Finally, the examples are given.
1993, 15(4): 425-430.
Abstract:
The definition of good codes for error detection is given- It is proved that linear block codes in GF(q) are good codes for error detection if and only if its dual codes are good ones also- A series of new results abour good codes for error detection is derived. New lower bounds on undetectable error probabilities of binary (n,k) linear block codes are obtained, which have no relation to the weight structure of the codes but only to n and k.
The definition of good codes for error detection is given- It is proved that linear block codes in GF(q) are good codes for error detection if and only if its dual codes are good ones also- A series of new results abour good codes for error detection is derived. New lower bounds on undetectable error probabilities of binary (n,k) linear block codes are obtained, which have no relation to the weight structure of the codes but only to n and k.
1993, 15(4): 431-434.
Abstract:
Experimental structure and results of a new type of solid-state power combiner with short focal length open cavity are presented in this paper. In X wave-band, the experiments use four Gunn diodes, with every two in series with electric field, whose rated CW power are 155 mW, 160 mW, 160 mW and 165 mW, respectively. The obtained experimental results show that the opening machine CW output power is over 1 W, stable CW output power is about 850 mW.
Experimental structure and results of a new type of solid-state power combiner with short focal length open cavity are presented in this paper. In X wave-band, the experiments use four Gunn diodes, with every two in series with electric field, whose rated CW power are 155 mW, 160 mW, 160 mW and 165 mW, respectively. The obtained experimental results show that the opening machine CW output power is over 1 W, stable CW output power is about 850 mW.
1993, 15(4): 435-440.
Abstract:
The relative convergence problem arouse in model matching method is discussed and a mode sorting technique is presented to solve this problem. Numerical examples demonstrated that this sorted mode matching method can not only solve the relative convergence problem, but also accelereate the convergence rate and has better accuracy than conventional mode matching method. Numerical results of the waveguide junction discontinuity using this method indicated that this method takes the advantages of stable, accurate and fast convergence.
The relative convergence problem arouse in model matching method is discussed and a mode sorting technique is presented to solve this problem. Numerical examples demonstrated that this sorted mode matching method can not only solve the relative convergence problem, but also accelereate the convergence rate and has better accuracy than conventional mode matching method. Numerical results of the waveguide junction discontinuity using this method indicated that this method takes the advantages of stable, accurate and fast convergence.
APPLICATION OF SWITCH-ON FUNCTIONS IN THE 2-D FDTD MODELING TIME-HARMONIC ELECTROMAGNETIC SCATTERING
1993, 15(4): 441-444.
Abstract:
When the time-harmonic electromagnetic scattering is modeled via the finite-difference time-domain (FDTD) technique, an additional switch-on function is introduced in order to reduce the ringing phenomenon for initial transient process in FDTD calculation. Some examples are given to demonstrate the feasibility.
When the time-harmonic electromagnetic scattering is modeled via the finite-difference time-domain (FDTD) technique, an additional switch-on function is introduced in order to reduce the ringing phenomenon for initial transient process in FDTD calculation. Some examples are given to demonstrate the feasibility.
1993, 15(4): 445-448.
Abstract:
Energy levels and wavefunctions in GaAs quantum wells are calculated by solving the Schrdinger equation using Numerov method, and their dependence on various parameters including well width, barrier height and external field are examined in detail. The obtained results are useful in study of electro-optic properties of GaAs/AlGaAs quantum well structures and the device design.
Energy levels and wavefunctions in GaAs quantum wells are calculated by solving the Schrdinger equation using Numerov method, and their dependence on various parameters including well width, barrier height and external field are examined in detail. The obtained results are useful in study of electro-optic properties of GaAs/AlGaAs quantum well structures and the device design.
