Showing papers in "Journal of Electronics (china) in 1985"
TL;DR: In this article, two topological expressions (A and B) and their proofs for generalk-order cofactor of the indefinite-admittance matrix of an active network are presented.
Abstract: In this paper, two topological expressions (A) and (B) and their proofs for generalk-order cofactor of the indefinite-admittance matrix of an active network are presented. The expression (A) is the unification and generalization of Chen's topological expressions (1965, 1976), for 1-,2-,3-order and specialk-order cofactors. The expression (B) shows that there is another topological analysis method for active networks—positive-rootedk-tree method.
3 citations
TL;DR: In this paper, a set of simple formulas and graphs for calculating both the radiation pattern bandwidth and the impedance bandwidth of a rectangular microstrip antenna are presented with experimental verification based on the cavity model theory.
Abstract: Based on the cavity model theory, a set of simple formulas and graphs for calculating both the radiation pattern bandwidth and the impedance bandwidth of a rectangular microstrip antenna are presented with experimental verification. Three kinds of approaches to broaden the bandwidth and their potentiality are reviewed and discussed. A simple broadband technique by means of combination of stub-matching and increasing the antenna thickness is developed. An experimental element with the thickness of 0.05 wavelength is matched by using two stubs, while the input VSWR is measured to be less than 2:1 over a 13% bandwidth.
3 citations
TL;DR: In this paper, a density of state distribution in pseudo-gap of phosphorus-dopeda-Si:H material prepared by glow-discharge method has been measured experimentally by deep level transient spectroscopy.
Abstract: A density-of-state distribution in pseudo-gap of phosphorus-dopeda-Si: H material prepared by glow-discharge method has been measured experimentally by deep level transient spectroscopy. A minimum value of 7×1015 cm−3 eV−1 has been obtained at the energy of about 0.5 eV belowE
c. This physical picture is quite different from the previous one obtained by field effect. Some comments on the method and the theoretical analysis are given.
2 citations
TL;DR: The performance of the frequency and time-domain adaptive filters are shown to be the same for an unknown frequency signal, but for the detection of known frequency the frequency- domain adaptive filter length is much shorter to get the same detection probability.
Abstract: The detection performance of the frequency-domain adaptive filter is compared with the time-domain one. Comparisons are based on the computer digital simulation with a sinusoidal signal and white Gauss noise. The performance of the frequency and time-domain adaptive filters are shown to be the same for an unknown frequency signal, but for the detection of known frequency the frequency-domain adaptive filter length is much shorter to get the same detection probability.
2 citations
TL;DR: In this paper, a proximity focused microchannel plate image-intensifier (MCP I2) was used as a fast optical shutter due to its high temporal and spatial resolution, large spectral and input intensity range, high gain as well as the possibility of transient recording of single-shot events.
Abstract: A proximity focused microchannel plate image-intensifier (MCP I2) can always serve as a fast optical shutter due to its high temporal and spatial resolution, large spectral and input intensity range, high gain as well as the possibility of transient recording of single-shot events
1 citations
TL;DR: In this article, the first harmonic interaction impedance from the data of large perturbation measurement is calculated using the CCTWT design program, which is a part of the programs for CCTW design.
Abstract: The formula and program for calculating the total and negative first harmonic interaction impedance from the data of “large perturbation measurement” are given. This program is a part of the programs for CCTWT design.
1 citations
TL;DR: In this paper, a modified Rowe's model was proposed to improve the accuracy of the design of TWTs, and all results obtained by the new model were more in agreement with the actual cases than those by Rowe's.
Abstract: Because of the nonconservation of energy in the Rowe's model for the large signal interaction in TWTs. The Rowe's model produces considerable error in the TWT design, especially, in the design of helix TWT with velocity jump. A modified model which is based on conservation of energy is suggested to improve the accuracy of the design of TWT. By the new model, when the loss and the space-charge are neglected, the energy got by the circuit is accurately equal to that given by the electron beam. And all results obtained by the new model are more in agreement with the actual cases than those by Rowe's model.
1 citations
TL;DR: The asymptotic performance of many detectors whose nonlinearity can more effectively suppress the tail of the noise envelope distribution is apparently better than that of the Neyman-Pearson optimum detector for narrowband Gaussian noise.
Abstract: The discrete-time detection of narrowband coherent and incoherent pulse train signals in narrowband non-Gaussian noise is investigated. The locally optimum (LO) detector structures are developed and found to be in the form of incorporating a locally optimum zero-memory nonlinearity (LOZNL) into the Neyman-Pearson optimum detector for narrowband Gaussian noise. Many practical detectors belong in the same class of structures with the LO detector. The expressions for the efficacies of the detectors are derived. In particular, Weibull and log-normal noise models are considered. The LOZNL’s, and the efficacies of the detectors are given, and numerical results are graphically presented. It is shown that, in the sense of the Pitman asymptotic relative efficiency (ARE), the asymptotic performance of many detectors whose nonlinearity can more effectively suppress the tail of the noise envelope distribution is apparently better than that of the Neyman-Pearson optimum detector for narrowband Gaussian noise.
1 citations
TL;DR: A digraph associated with an indefinite matrix is augmented and both the first-order and second-order cofactors can be obtained by finding all the directed trees in the augmented digraph and eliminating the need of computing the directed 2-trees for the second-orders.
Abstract: A digraph associated with an indefinite matrix is augmented. Both the first-order and second-order cofactors can be obtained by finding all the directed trees in the augmented digraph and eliminating the need of computing the directed 2-trees for the second-order cofactors. The technique proposed here is particularly applicable to computer-programming.
1 citations
TL;DR: In this paper, the dispersion characteristics of rectangular waveguides filled with arbitrary block-shaped dielectrics are calculated by the method of finite element, and a generalized program is given for the hybrid dominant and higher order modes.
Abstract: The dispersion characteristics of rectangular waveguides filled with arbitrary block-shaped dielectrics are calculated by the method of finite element. A generalized program is given for the hybrid dominant and higher order modes. More than ten different rectangular waveguides loaded with various dielectric distributions have been investigated, and the results verify the reliability of the program. In particular, the useful bandwidth of the waveguide filled with I-shaped dielectric is analyzed in detail. The dispersion curves given in this paper are useful for analyzing and designing related microwave components of current interest.
1 citations
TL;DR: Simulation results and experimental data are included to show the feasibility of the computerized technique including time sampling and phase adjustment for wideband radar array imaging.
Abstract: A computerized technique including time sampling and phase adjustment is developed for wideband radar array imaging. Algorithms are given for examination of errors due to time sampling. FFT is introduced to speed up the imaging processing with a periodic array. Simulation results and experimental data are included to show the feasibility of the technique.
TL;DR: In this article, the dyadic Green's functions for generalized cylinders in free space were derived with the technique in another paper of author (1984), where dyadic green functions for conducting wedges, half-plates and elliptic cylinders, whose integral of continuous spectrumh has been eliminated, are given particularly.
Abstract: Dyadic Green’s functions are powerful and efficient for solving the boundary problems in electromagnetic theory. The key problem involved is how to deal with the additional term in the electric dyadic Green’s function at the source region. In this paper, the dyadic Green’s functions for generalized cylinders in free space are derived with the technique in another paper of author (1984). The dyadic Green’s functions for conducting wedges, half-plates and elliptic cylinders, whose integral of continuous spectrumh has been eliminated, are given particularly.
TL;DR: It is shown that both the memory capacity and the computing time of the computer are greatly saved by using techniques for solving electro-magnetic scattering problems of dielectric cylinders of arbitrary cross sections by the unimoment method.
Abstract: Computer techniques for solving electro-magnetic scattering problems of dielectric cylinders of arbitrary cross sections by the unimoment method are investigated. In the solution of the fields inside the mathematical circle, a computer program for the realization of Ricatti transformation in solving the linear algebraic equations is programmed. With the case of a rectangular cylinder as an example, automatic generation of finite element mesh for Ricatti transformation is achieved. It is shown that both the memory capacity and the computing time of the computer are greatly saved by using these techniques. The previous procedure of the finite element method is also greatly simplified.
TL;DR: A modified time domain orthogonality algorithm (MTDO) for adaptive filters is presented and described and the performance of spectral estimates of the MTDO adaptive system is obtained by us experimentally and compared with the least mean square algorithm adaptive system.
Abstract: A modified time domain orthogonality algorithm (MTDO) for adaptive filters is presented and described. The results of computer simulation show that the algorithm has two characteristics: 1. the same convergence factorc can be used within a fairly wide range of signal to noise ratio (SNR) of input signal. 2. MTDO adaptive noise canceller has a useful characteristic, i. e. at the same signal to noise ratio of input desired signal the input reference signal power is uncorrelated with the convergence factorc. Therefore one adaptive noise canceller can be used more flexibly. The performance of spectral estimates of the MTDO adaptive system is obtained by us experimentally and compared with the least mean square algorithm adaptive system.
TL;DR: In this paper, the influence and effective method of treatment for another important high order mode H21o have not been solved, and a broadband H 21o, E01o mode filter has been proposed.
Abstract: Recently, the influences of high order mode E01o and transimission characteristics of H11o multimode circular bend waveguide used in a high performance Cassegrainian microwave antenna, which utilized an offset excited horn-feeder, for the antenna and feed system of 4,5 and 6 GHz bands have been studied and analyzed by N. Nakajima, et al. But in their paper, the influence and effective method of treatment for another important high order mode H21o have not been solved. In this paper, higher order modes coupling characteristics in H11o circular bend waveguide are analyzed according to the coupled wave equations and coupling coefficients of E01o, H21o modes and their amplitudes are computed. A broadband H21o, E01o mode filter has thereby been proposed. Experimental results indicated that it performs well in practical application. Thus, the problems still confronting N. Nakajima et al. are capable of being solved thoroughly.
TL;DR: In this article, a 2/3 injection locking VHF divider consisting of the FZ1C, a type of IC, is developed, with a stability factorn=δf(3/2)max/Δf(−40−+85°C);⩾4 while for the original circuit,n≈0.6.
Abstract: Compared with the harmonic injection locking (HIL), a rational harmonic injection locking (RHIL) can make the circuit even simpler and more flexible. A common formula for the synchronizing band Δω(
s,m
)max of the RHIL is derived and analysed in this paper. The result shows that the formula given by Schmideg (1971) is only its special case. A method for extending the RHIL’s synchronizing band with full-pass network is presented. Using the method, a 2/3 injection locking VHF divider consisting of the FZ1C, a type of IC, is developed, with a stability factorn=δf(3/2)max/Δf(−40−+85°C);⩾4 while for the original circuit,n≈0.6. Thus, the RHIL may be of more practical value in applications.
TL;DR: In this article, a matched filter using CCD for PCM is made and the experimental results of output waveform, transfer function and output signal-to-noise ratio are given and compared with the theoretical ones.
Abstract: A matched filter using CCD for PCM is made. The experimental results of output waveform, transfer function and output signal-to-noise ratio are given and compared with the theoretical ones. The output signal-to-noise ratio for the non-return-to-zero codes is 1 dB below the theoretical value.
TL;DR: In this paper, an accurate solution of the characteristic impedance of the elliptic strip-line with conformal transformation is developed, and some data are given, which are useful for designing elliptIC strip-lines.
Abstract: An accurate solution of characteristic impedance of the elliptic strip-line with conformal transformation is developed. Some data are given, which are useful for designing elliptic strip-lines.
TL;DR: In this paper, the odd and even mode propagation constants of uniformly coupled trapped image waveguides are calculated by using the methods of the effective dielectric constant and surface impedance matching.
Abstract: The odd and even mode propagation constants of uniformly coupled trapped image waveguides are calculated by using the methods of the effective dielectric constant and surface impedance matching. Theoretical characteristics of a coupler made of coupled trapped image waveguides are analyzed and they can be used as a foundation for the design of this kind of coupler.
TL;DR: In this paper, the negative electric effects of La metal at Si-SiO2 interface and the heat treatment behavior of these effects are studied experimentally and the results of electron spectroscopy analysis of the La-doped interfaces are also presented.
Abstract: The negative electric effects of La metal at the Si-SiO2 interface and the heat treatment behavior of these effects are studied experimentally. In addition, the results of electron spectroscopy analysis of the La-doped interfaces are also presented.
TL;DR: In this article, a technique of symmetry analysis for modal characteristics in uniform waveguides or resonators with ferrite rods is presented, and results of the symmetry analysis are given in four tables.
Abstract: A technique of symmetry analysis for modal characteristics in uniform waveguides or resonators with ferrite rods is presented here. Symmetry analysis can provide basic information concerning modal characteristics. After summarizing the basic principles of symmetry analysis, some points concerning symmetry operations are discussed. Then the process of symmetry analysis is applied to structures, i.e. uniform wave guides withC
n
symmetry or
$$C_{n_v } $$
symmetry and resonators withD
nh
symmetry in which exist longitudinally magnetized ferrite rods. Finally, results of the symmetry analysis are given in four tables.
TL;DR: In this article, a modified conventional RF sputtering equipment is used in preparing the Al2O3 antireflection (AR) coating, and an increase in the light output by 30-60% at a driving current of 200 mA for the GaAs-GaAlAs DH LEDs with a AR coating thickness of about λ/4 has been obtained.
Abstract: A modified conventional RF sputtering equipment is used in preparing the Al2O3 antireflection (AR) coating. An increase in the light output by 30–60% at a driving current of 200 mA for the GaAs-GaAlAs DH LEDs coated on the front faces with a AR coating thickness of about λ/4 has been obtained. Under the same AR coating conditions a light output increase of less than 30% for the degraded LEDs of the same type has been determined. It may probably be attributed to the defects formed in the bulk of the Ga1−xAlxAs crystals caused by degradation of diodes which restricts light output increase.
TL;DR: In this paper, the reflective coefficient of diffraction in the open-end of resonators with slowly varying cross-section under general unsymmetrical mode conditions can be found by introduction of a phase correction factor.
Abstract: By using the method of transverse-section, the reflective coefficient of diffraction in the open-end of resonators with slowly varying cross-section under general unsymmetrical mode conditions can be found by introduction of a “phase correction factor” Diffraction boundary conditions in the open-end are obtained, and can be used to solve multimode problems Several different types of open resonators are studied, and the methods of engineering calculation are also briefly discussed
TL;DR: A new lower bound for the minimum distance of binary Goppa codes is shown and it is shown that this lower bound improves the results in Y. Sugiyama and Feng Guiliang's papers.
Abstract: Binary Goppa codes are a large and powerful family of error-correcting codes But how to find the true minimum distance of binary Goppa codes is not solved yet In this paper a new lower bound for the minimum distance of binary Goppa codes is shown This new lower bound improves the results in Y Sugiyama (1976) and Feng Guiliang's (1983) papers The method in this paper can be generalized to other Goppa codes easily
TL;DR: A set of programs is established for IMPATT (Impact Avalanche Transit Time) diode simulation and the physical principles, numerical methods and program design are discussed, and the half-implicit method is presented in detail.
Abstract: A set of programs is established for IMPATT (Impact Avalanche Transit Time) diode simulation. It can be used to obtain the DC small and large signal solution of the IMPATT diodes made of different materials and having different doping profiles. The physical principles, numerical methods and program design are discussed, and the half-implicit method is presented in detail. Those programs can be used to simulate all kinds of transit-time devices, but the calculation results only of the Si IMPATT Diode are given.
TL;DR: A general approach is presented as regards the frequency-domain analysis of SC networks, pointing out that the SC network can be modeled by an analogue circuit consisting of amplifiers, resistors and capacitors with real constant element values using scaling transformation and bilinear transformation (Pauper's algorithm).
Abstract: A general approach is presented as regards the frequency-domain analysis of SC networks. At first the scaling property of SC network is discussed. From the scaling property it is pointed out that the SC network can be modeled by an analogue circuit consisting of amplifiers, resistors and capacitors with real constant element values using scaling transformation and bilinear transformation (Pauper's algorithm). Thus the SC network frequency response and sensitivity can be calculated by calling available standard analogue circuit analysis program. The proposed algorithm has the advantage of small computing time in comparison with existing methods.
TL;DR: Based on the recognition requirement to suppress types of noise created in the conversion process of handwritten characters into binary patterns in optical character recognition, an algorithm of processing digital character noise is presented.
Abstract: Based on the recognition requirement to suppress types of noise created in the conversion process of handwritten characters into binary patterns in our optical character recognition, an algorithm of processing digital character noise is presented. The software and hardware of the algorithm is described.
TL;DR: In this article, a mathematical model of the circularly polarized feed was developed and the approach for the Jacobi-Bessel series expansion of the physical optics radiation integral studied by R. Mittra et al. is extended to the case of circular polarizition.
Abstract: A mathematical model of the circularly polarized feed is developed in this paper. The approach for the Jacobi-Bessel series expansion of the physical optics radiation integral studied by R. Mittra et al. is extended to the case of circular polarizition. A computation method for the circularly polarized contoured beam of the offset reflector antennas is analysed. Representative numerical result is given for effective isotropic radiated power contour-plot of the western zone coverage of Chinese territory by the 7-element array illumination.
TL;DR: In this article, the characteristics of general quaternary phase shift keying (QPSK) modulation are analyzed using the clockwise or anticlockwise stepping pulse code signal, and the spectrums in several operational conditions and the admittance formulas of related two modulation circuits are calculated.
Abstract: Using the clockwise or anticlockwise stepping pulse code signal, the characteristics of general quaternary phase shift keying (QPSK) modulation are analysed. This paper gives the spectrums in several operational conditions and the admittance formulas of related two modulation circuits. Several typical examples of QPSK modulation are calculated. The modulation effect and the phase error can be decided and the QPSK modulator under the dynamic test may be adjusted by using above results. The experimental results are in agreement with the theoretical calculations. An X-band QPSK modulator is also presented. The maximum phase error is less than 4°, the phase accuracy near ±0.1°, the insertion loss less than 4 dB and the data (transfer) rate up to 68 Mb/s.
TL;DR: The properties of the loop is analyzed mathematically and the formulas to determine the sensibility and other parameters are derived and the dynamic features of some examples are shown.
Abstract: In this paper, an auto-gain-control (AGC) loop which operates in a digital correlating receiver is described. The properties of the loop is analyzed mathematically and the formulas to determine the sensibility and other parameters are derived. The static and dynamic features of some examples are shown. The procedure for designing such a gain control loop is discussed.