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1993 Vol. 15, No. 5
Display Method:
1993, 15(5): 449-457.
Abstract:
A new concept, the generalized inverse group (GIG) of signal, is firstly proposed and its properties, leaking coefficients and implementation with neural networks are discussed in this paper. Theoretical analysis and computational simulation show that (1) there are a group of finite length generalized inverse signals for any finite signal, which form the GIG; (2) each inverse group has different leaking coefficients, thus different abnormal states; (3) each GIG can be implemented by a grouped and improved single-layer percep- tron which appears with fast convergence. When used in deconvolution, the proposed GIG can form a new parallel finite length filtering deconvolution method. On off-line processing, the computational time is reduced to O(N) from O(N2).And the less leaking coefficient is, the more reliable the deconvolution will be.
A new concept, the generalized inverse group (GIG) of signal, is firstly proposed and its properties, leaking coefficients and implementation with neural networks are discussed in this paper. Theoretical analysis and computational simulation show that (1) there are a group of finite length generalized inverse signals for any finite signal, which form the GIG; (2) each inverse group has different leaking coefficients, thus different abnormal states; (3) each GIG can be implemented by a grouped and improved single-layer percep- tron which appears with fast convergence. When used in deconvolution, the proposed GIG can form a new parallel finite length filtering deconvolution method. On off-line processing, the computational time is reduced to O(N) from O(N2).And the less leaking coefficient is, the more reliable the deconvolution will be.
1993, 15(5): 458-465.
Abstract:
A fast separable approach based on a cross array is presented which has coarsegrained parallelism. Its computational load is far less than that of the two-dimensicmal direct processing method and other existing separable approaches. In order to compensate for the performance degradation due to separable processing, two postprocessing schemes are also proposed. Some computer simulation results are provided for illustration in the end.
A fast separable approach based on a cross array is presented which has coarsegrained parallelism. Its computational load is far less than that of the two-dimensicmal direct processing method and other existing separable approaches. In order to compensate for the performance degradation due to separable processing, two postprocessing schemes are also proposed. Some computer simulation results are provided for illustration in the end.
1993, 15(5): 466-474.
Abstract:
A new mathematical model, the linear homogeneous equations with polynomial coefficients for describing the synthesis problem, is presented in this paper. It gives a nature approach ro generalize the linear synthesis to nonlinear case. This method is used ro obtain a new solution for the multisequence synthesis. The Grbner bases theory in polynomial ring is used to present an efficient algorithm for the mathematical model. This turns out to be a generalization of Euclid algorithm. However, the new one has much brilliant prospects. As one of the important results, it is discovered that the new algorithm can be used to deduce an efficient decoding algorithm for a class of algebraic geometry codes constructed by Justesen, so the important open problem is solved.
A new mathematical model, the linear homogeneous equations with polynomial coefficients for describing the synthesis problem, is presented in this paper. It gives a nature approach ro generalize the linear synthesis to nonlinear case. This method is used ro obtain a new solution for the multisequence synthesis. The Grbner bases theory in polynomial ring is used to present an efficient algorithm for the mathematical model. This turns out to be a generalization of Euclid algorithm. However, the new one has much brilliant prospects. As one of the important results, it is discovered that the new algorithm can be used to deduce an efficient decoding algorithm for a class of algebraic geometry codes constructed by Justesen, so the important open problem is solved.
1993, 15(5): 475-481.
Abstract:
Based on the fact that it has nodifficulty to achieve ultra-low Sidelobe for Doppler filiter, a simplified auxiliary channel approach, whose performance is the same as that of Klemm s method but the reduction ofcomputation load is great, is described in this paper.
Based on the fact that it has nodifficulty to achieve ultra-low Sidelobe for Doppler filiter, a simplified auxiliary channel approach, whose performance is the same as that of Klemm s method but the reduction ofcomputation load is great, is described in this paper.
1993, 15(5): 482-486.
Abstract:
A design technique for high-pass filters using OTA differentiator is presenred. By means of the leapfrog synthesis of the active filters, the OTA-C realization of the highorder high-pass filters is built up. The filter is compatible with MOS process. It has low sensitivity performance and high cut-off frequency, and can be tuned conveniently by the external voltages. Experimental results and P-SPICE simulation are given to prove its feasibility
A design technique for high-pass filters using OTA differentiator is presenred. By means of the leapfrog synthesis of the active filters, the OTA-C realization of the highorder high-pass filters is built up. The filter is compatible with MOS process. It has low sensitivity performance and high cut-off frequency, and can be tuned conveniently by the external voltages. Experimental results and P-SPICE simulation are given to prove its feasibility
1993, 15(5): 487-492.
Abstract:
The differential measuring mode for minority carrier diffusion length of aSi:H film by SPV technique can eliminate the influence of back juction of the sample. This paper analyses mathematical model of such mode, deduces formula for practical use, and discusses various elements which affect the measured results.
The differential measuring mode for minority carrier diffusion length of aSi:H film by SPV technique can eliminate the influence of back juction of the sample. This paper analyses mathematical model of such mode, deduces formula for practical use, and discusses various elements which affect the measured results.
ANGULAR SPECTRUM PROPERTY OF SPONTANEOUS EMISSION IN A TWO-DIMENSIONAL UNDULATOR FREE-ELECTRON LASER
1993, 15(5): 493-499.
Abstract:
The angular spectrum of spontaneous emission in a wo-dimensional undulator free-electron laser is analyzed theoretically. Numerical calcularion shows that the s-th harmonic spontaneous emission power density can be greatly enhanced by using a two-dimensional undulator, for which l=s. so the harmonic number can be selected by selecting l. Therefore, the higher harmonic operation of a free-electon laser can be realized selectively.
The angular spectrum of spontaneous emission in a wo-dimensional undulator free-electron laser is analyzed theoretically. Numerical calcularion shows that the s-th harmonic spontaneous emission power density can be greatly enhanced by using a two-dimensional undulator, for which l=s. so the harmonic number can be selected by selecting l. Therefore, the higher harmonic operation of a free-electon laser can be realized selectively.
1993, 15(5): 500-505.
Abstract:
The cyclotron autoresonance maser (CARM) has been developed which is a high power device operating at short wavelength. In this paper, the basic principle of CARM is described, and the design method and numerical calculation results for Bragg cavity are shown. Based on the distributed reflection performance of the corrugated waveguide, an important parameters S is found with application of coupled-wave theory. S parameter is used simply to design a Bragg cavity and to select one of the operation modes. Finally some discussions are made.
The cyclotron autoresonance maser (CARM) has been developed which is a high power device operating at short wavelength. In this paper, the basic principle of CARM is described, and the design method and numerical calculation results for Bragg cavity are shown. Based on the distributed reflection performance of the corrugated waveguide, an important parameters S is found with application of coupled-wave theory. S parameter is used simply to design a Bragg cavity and to select one of the operation modes. Finally some discussions are made.
1993, 15(5): 506-511.
Abstract:
A Cassegrain antenna with frequency seletctive reflector is introduced, and the measured radiation properties and radar cross-section (RCS) of the antenna are give and discussed. In comparison with ordinary metailic reflector, this antenna can obtain similar radiation pattern and about 15dB of RCS reduction.
A Cassegrain antenna with frequency seletctive reflector is introduced, and the measured radiation properties and radar cross-section (RCS) of the antenna are give and discussed. In comparison with ordinary metailic reflector, this antenna can obtain similar radiation pattern and about 15dB of RCS reduction.
1993, 15(5): 512-518.
Abstract:
A differential equation for the reflection coefficient of a continuously varied medium is derived by using a network theory, from which an approximation for reconstructing the permittivity profiles is obtained in closed form. Furthermore, the equivalem S scattering parameters of an arbitrary medium are given, based on which the permittivity profiles of an arbitrary continuous medium can be reconstructed in layered regions. Reconstruction examples show the validity of this method.
A differential equation for the reflection coefficient of a continuously varied medium is derived by using a network theory, from which an approximation for reconstructing the permittivity profiles is obtained in closed form. Furthermore, the equivalem S scattering parameters of an arbitrary medium are given, based on which the permittivity profiles of an arbitrary continuous medium can be reconstructed in layered regions. Reconstruction examples show the validity of this method.
1993, 15(5): 519-522.
Abstract:
A current-mode MOS neuron circuit with 4-bit programmable weights is presented using CMOS tetchnology. The weights of the neuron have high resolution and also can easily be digitally stored. The resolution can be extended into higher levels such as 8-bits, etc. by the design methodology presented in this paper. The operation principle of the neuron is discussed. Circuit simulation has been made by use of SPICE Ⅱ. The results give a good agreement for the design requirements.
A current-mode MOS neuron circuit with 4-bit programmable weights is presented using CMOS tetchnology. The weights of the neuron have high resolution and also can easily be digitally stored. The resolution can be extended into higher levels such as 8-bits, etc. by the design methodology presented in this paper. The operation principle of the neuron is discussed. Circuit simulation has been made by use of SPICE Ⅱ. The results give a good agreement for the design requirements.
1993, 15(5): 523-526.
Abstract:
A new algorithm for generating k-ary M sequences is given. Not the classical method that the main cycle is extended by joining to it one cycle but a new method that the main cycle is exended by joining to it a subset of cycles is used in the algorithm. The algorithm reduces the time of choosing bridging states, and accelerates the speed of joining cycles.
A new algorithm for generating k-ary M sequences is given. Not the classical method that the main cycle is extended by joining to it one cycle but a new method that the main cycle is exended by joining to it a subset of cycles is used in the algorithm. The algorithm reduces the time of choosing bridging states, and accelerates the speed of joining cycles.
1993, 15(5): 527-531.
Abstract:
A new universal tunable high-order OTA-C filter based on a signal-flow-graph realization of the transfer function is designed. The filter needs only OTAs and grounded capacitors, and it is convenient for realization with MOS technology. Experimental results are given to show its feasibility.
A new universal tunable high-order OTA-C filter based on a signal-flow-graph realization of the transfer function is designed. The filter needs only OTAs and grounded capacitors, and it is convenient for realization with MOS technology. Experimental results are given to show its feasibility.
1993, 15(5): 532-535.
Abstract:
Based on a set of reverse recovery charge curves and a set of reverse energy loss curves, a new method for calculating the reverse recovery current parameters of the thyritor turn off model is given, In a wide range of di/dt and IF the error of this calcaiating method is less than that of the other traditional methods. Therefore, this method has certain value for actual applications.
Based on a set of reverse recovery charge curves and a set of reverse energy loss curves, a new method for calculating the reverse recovery current parameters of the thyritor turn off model is given, In a wide range of di/dt and IF the error of this calcaiating method is less than that of the other traditional methods. Therefore, this method has certain value for actual applications.
1993, 15(5): 536-540.
Abstract:
The irradiation defects in Si wafer introduced by fast neutron can be used to act as nuclei of oxygen precipitation. These defeccts accelerate the formarion of oxygen precipitation in denuded region as well as getting irapurity region, thus haze dtfects on Si wafer can be restraint effectively. In this paper, a more practicable annealing technology and a brief interpretation are given.
The irradiation defects in Si wafer introduced by fast neutron can be used to act as nuclei of oxygen precipitation. These defeccts accelerate the formarion of oxygen precipitation in denuded region as well as getting irapurity region, thus haze dtfects on Si wafer can be restraint effectively. In this paper, a more practicable annealing technology and a brief interpretation are given.
1993, 15(5): 541-545.
Abstract:
The dispersion and loss characteristics of groove guide with arbitrary shapes are analyzed with high-order finite element method. The effectiveness and the reliability of the method are verified by the experiments and the results obtained by other mehods. Groove guides with various groove shapes, such as reorangular, triangular, parabolic, elliptic and cosine functions are investigated systematically. The calculating results show that the dispersion of groove guide with different groove shape is almost the same; the loss characteristic is rather different, among them. V-shape groove has the lowest loss, which is about half of the loss of rectangular groove guide. All the curves and .the data given in this paper can be used in designing the elements and circuits composed of the groove guide.
The dispersion and loss characteristics of groove guide with arbitrary shapes are analyzed with high-order finite element method. The effectiveness and the reliability of the method are verified by the experiments and the results obtained by other mehods. Groove guides with various groove shapes, such as reorangular, triangular, parabolic, elliptic and cosine functions are investigated systematically. The calculating results show that the dispersion of groove guide with different groove shape is almost the same; the loss characteristic is rather different, among them. V-shape groove has the lowest loss, which is about half of the loss of rectangular groove guide. All the curves and .the data given in this paper can be used in designing the elements and circuits composed of the groove guide.
1993, 15(5): 546-550.
Abstract:
The propagation characteristics of circular waveguide filled with multilayer chiral tnedia is analyzed by recursive eighenfunction method in this paper. A recursive formula for dispersion characteristics of circular waveguide filled with N-layer chiral media is derived. As examples, calculated results for several cases are also presented.
The propagation characteristics of circular waveguide filled with multilayer chiral tnedia is analyzed by recursive eighenfunction method in this paper. A recursive formula for dispersion characteristics of circular waveguide filled with N-layer chiral media is derived. As examples, calculated results for several cases are also presented.
1993, 15(5): 551-555.
Abstract:
Resonant characteristic of eccentric ring microstrip antennas has been studied using point-matching moded. The formulation can be appplied to some specific cases, for example, circular, circular ring and eceentric circular ring patch antenna. The good agreement between measured and calculated results of resonant wave-number of eccentric circular ring microstrip antenna indicates that the method can be used to analyse characteristic of arbitrary shape microstrip antennas.
Resonant characteristic of eccentric ring microstrip antennas has been studied using point-matching moded. The formulation can be appplied to some specific cases, for example, circular, circular ring and eceentric circular ring patch antenna. The good agreement between measured and calculated results of resonant wave-number of eccentric circular ring microstrip antenna indicates that the method can be used to analyse characteristic of arbitrary shape microstrip antennas.
1993, 15(5): 556-560.
Abstract:
The complex ray theory for three-dimensional space is researched, from which the method of complex ray tracing for arbitrary configuration in three-dimensional space is derived, and the beam transmission properties of a rotating parabolic radotne are solved. According to the data calculated. the patterns of the beam transmitted through a rotating parabolic radome are plotted. Then they are compared with the patterns without radome and the effects of radome on the beam transmission is depicted.
The complex ray theory for three-dimensional space is researched, from which the method of complex ray tracing for arbitrary configuration in three-dimensional space is derived, and the beam transmission properties of a rotating parabolic radotne are solved. According to the data calculated. the patterns of the beam transmitted through a rotating parabolic radome are plotted. Then they are compared with the patterns without radome and the effects of radome on the beam transmission is depicted.
