最新刊期
卷 ， 期 3 ， 1982
- 摘要：A new corrugated guide horn having dual-slot depth corrugations was proposed by Carpenter and Ghosh in 1980. It is suitable for achieving improved performance over a wide-band or a discrete multi-band.This paper describes a space-harmonic analysis of this new device, and develops a formula of the equivalent admittance which has taken into consideration the relation between the fields in two slots of the dual depth corrugations. The method for predicting the eigenvalue has been introduced, and the predicted performances of this new horn have been given.2|120|13更新时间：2025-12-08
- 摘要：This paper discusses the relation of the range-rate error with oscillator frequency stability in different range-rate measuring systems. The formulas of the random phase power spectra density of the Doppler signal at the input of the range-rate measuring terminal are obtained from the random phase power spectra density of the frequency sources restrained by the transfer function of the range-rate measuring system. In this paper, the relations both of the variance of the range-rate samples and of the error covariance matrixes of the range-rate smoothed by least square method with the oscillator stability are given.2|46|1更新时间：2025-12-08
- 摘要：A new multiple valued logic circuit （MV-DYL） has now developed, which is an excellent multiple valued logic cell[3]. All logic design programs for MV-DYL circuits are presented further in this paper, and it is proved by our experiments that the operations are reliable and the properties are stable.A high-speed AND-OR universal array of multiple valued logic is proposed, and 10100 different decimal logic functions of two variables can be realized by use of 100 MV-DYL AND gates regularly arranged.2|35|13更新时间：2025-12-08
- 摘要：The control charts of a new type known as proposed by the author in referen-ce[1] cause selecting control charts, further divide the assignable causes under Shewhart’s meaning into those to be controlled and those not to be controlled, and then can select out the former only and exert control over them, but neglect the latter. According to the number of assignable causes not to be controlled, the cause selecting control charts can be divided into the single and the multiple ones.On the basis of reference[1], this paper offers the multiple cause selecting control charts illustrating its computing methods and theoretical basis.The multiple cause selecting control charts are more flexible and more adaptable than the single ones, and it is possible to reduce the computations of cause selecting control charts in their applications.2|99|12更新时间：2025-12-08
- 摘要：A prediction-decision fault analysis method is presented in this paper. If the number of faults in a circuit does not greater than the number of ports, the faults can be analysed by this method only using some algebraic computations. But if there have some loops or cut sets between these fault branches, solving a set of nonlinear equations is also necessary, though the number of variables is much decreased.2|49|21更新时间：2025-12-08
- 摘要：In this article, it is first shown that two fundamental parameters, the voltage-feedback coefficient η under constant collector current and the current-feeback coefficient σ under constant base-emitter voltage are most suitable for a complete and rigorous description of the Early-effect of a transistor, and the low-frequency small-signal circuit parameters can readily be derived from them.For the general case where the impurity profile in the base region is arbitrary, η can be expressed in terms of the effective base-doping charge Qb and the transition capacity Cc of the collector junction, and a can be expressed in terms of Qb and the base transit time tb of the transistor. For a planer transistor with a Gaussian base-doping profile, a series of graphs is given, available for evaluating η, σ, Cc, tb and other small-signal circuit parameters. The case of a lateral pnp transistor is also discussed, and a numerical example is given. This article is ended with a brief discussion of the so-called Early-voltage and its relation to coefficients η and σ.2|78|4更新时间：2025-12-08
- 摘要：Ideal waveguide coupled mode equations derived by Marcuse have been extended to multi-waveguide coupled systems in this paper. On this basis input and output coupling properties have been described systematically by coupled mode theory of guided mode and radiation mode. Under weak coupling conditions, our theory is agree with Tien and Ulrich’s plane wave analysises.2|106|1更新时间：2025-12-08
- 摘要：In this paper, the parasitic AM and phase error in 0-π phase modulated signals are analyzed. The influence of these incidental modulations on PRC ranging systems is discussed. The point, which is investigated with emphasis, is that the distortional signals are expressed as a sum of two components: One is an available modulated signal, and the other is a non-modulated carrier. A ranging equation formulated by these two components is derived.2|80|3更新时间：2025-12-08
- 摘要：A general outline of the development of speech communication related to the techniques of speech signal processing was given briefly. The development of speech signal processing techniques was divided into three steps: 1)waveform processing; 2)parameter processing; 3)information processing. It is considered that the potentiality of waveform processing of speech is limited, the model of parameter processing of speech has to be developed, and the information processing of speech is still a virgin field.Some methods of evaluation and diagnosis for speech transmission quality were reviewed and looked forward for vast vistas of speech communication in this paper.2|113|1更新时间：2025-12-08
- 摘要：A new injection-locking oscillator using differential amplifier is described. Utilized as an amplifier or divider, it has good stability, wide synchronous range and high translation gain. In this paper, a mathematical model is developed for it, and the principles and amplitude-frequency responses of various modes are analyzed by averaging method. The calculation equations of synchronous range and the general expression of phase equations are also given. Finally, the experimental results are presented.2|35|5更新时间：2025-12-08
- 摘要：A frequency synthesizer for Hydrogen atom frequency standard which has variable six digits has been developed. The frequency of this synthesizer can be changed from 405700.0000Hz to 405799.9999Hz with a minimum step frequency of 1 ×10-4Hz. The measured results show that nonharmonic interrelated spurious output of the synthesizer is less than -85dB. The measured short term frequency stabilities σ（τ） are 2.07×10-11, 2.48× 10-12 and 2.88×10-13 for averaging time of 0.1s, Is and 10s respectively. The phase drift of the synthesizer, △φ, is 28.8° when the ambient temperature varies from 20℃ to 40℃. No change in output phase of the synthesizer was observed when the supply-voltage varied either from + 16V to + 19V or from +5V to +6V. The experiments show that it can operate continuously for more than one month without troubles, and can operate normally for ambient temperatures from 0℃ to 55℃.2|21|0更新时间：2025-12-08
- 摘要：After having accurately analyzed the difficulties during the frequency conversion,we introduced a reasonable phase-locked frequency stabilization mode and carried out a careful adjustment. Thus, a microwave signal at 5cm band was successfully heterodyned directly to 0.01Hz by means of a "long step" frequency conversion technique. It was observed from the low frequency signal on the microwave mixer that the wave form was clear and stable. Having been tested and analyzed with the frequency and time domain methods, the low frequency signal proved to be ideal.2|20|0更新时间：2025-12-08
- 摘要：This paper presents a detector-amplifier with a wide dynamic range （about 80 dB） and high sensitivity, and discusses its characteristics of low-noise detection and amplification. The En-In noise model is analysed, based on this analysis the low-noise design principles are developed and three low-noise properties of the detector-amplifier are discussed.Expressions for the detecting sensitivity, dynamic range, etc. are derived by use of the modified Bessel function and the expansion of its series. Some examples of its practical application are also given.2|48|0更新时间：2025-12-08
- 摘要：In order to meet the needs of electron emitter’s surface study, a simple and convenient AES apparatus has been made. Some oxide cathodes and active Ni substrates were studied by means of this apparatus.lt was observed that the relative atomic concentration of Ba and Sr changed significantly before and after activation. And this change is related to the surface segregation of the activating agents in active Ni. A fully-activated cathode has greater amount of BaO than SrO in the coating surface layer and "excess" Ba also appears in this region.2|31|0更新时间：2025-12-08
- 摘要：The microwave solid-state noise diode presented in this paper is designed based on Hines’ avalanche noise theory of Read diode, and Haitz’ and Voltmer’s expression for the noise spectral power density at microwave band.Various design considerations, such as excess noise, avalanche frequency, frequency-dependant excess noise, temperature-dependant excess noise and diode impedance. Based on such a design, a specific solid-state noise diode is developed, whose noise performance is controllable. A microwave coaxial solid-state noise source using this diode is also made, featuring broad bandwidth, small size, light weight, variable noise output and low power consumption.2|105|5更新时间：2025-12-08
- 摘要：In a study we observed a variety of LED by SEM and investigated four types of defects in p-n juction and near by. They are dark points, mechnical scars, twin crystals and misfit dislocations. We analysed their effects on photo-electric properties such as non-radiative recombination behaviour of dislocation and twin crystal. Effects of dislocation on luminescence efficiency, life time and ageing characteristics of LED and on V-I characteristics were also analysed.2|66|6更新时间：2025-12-08
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0