最新刊期
卷 ， 期 1 ， 1981
- 摘要：The optimal processing of the multi-parameter spacetime sampled radar signal is discussed using the vector space approach. It is shown that the optimal processing system is a spacetime matched system and is the extension, of the classical theory. The signal detec-tability of that system is determined mainly by the signal-to-noise ratio, and the accuracy of parameter estimation is also related to the characters of the generalized ambiguity function.3|33|0更新时间：2025-12-08
- 摘要：This paper presents some multi-criterion concurrently-optimal （2, 1, 31） and （3, 1, 31） nonsystematic convolutional codes for sequential decoding. These codes are constructed with a computer using an algorithm of constructing nonsystematic convolutional codes found by Zhang Zhao-zhi. Some of convolutional code generators are given. The minimum distance dc（m） and column distance profile dc（0, h） of these codes are found to be optimal. The free distance d, of the （2, 1） code is made up to 29-30, and of the （3, 1） code up to 47-49. All of the multi-criterion concurrently-optimal nonsystematic convolutional codespresented in this paper are intransparent with the greatest column inverse-distance dc（m） so that we. will be able to reduce the computational, requirements for recognizing the 180° phase-ambiguity in sequential decoding. The （3, 1, 31） nonsystematic code presented in this paper has concurrently-optimal performance for both 1/2 and 1/3 coding rates.2|26|1更新时间：2025-12-08
- 摘要：A detailed investigation about the two methods of kinetic theory of ECRM is given in this paper. One of them based on integration in the waveguide coordinate system was presented by the scientists of NRL of America, and the other based on the local field expansion in the electron guiding center coordinate system was proposed by the author of the present paper. After detailed analysis and comparison with these two methods, the paper points out that the later one has some advantages over the first one; it approaches more simply and directly, and has more explicit physical meaning. Furthermore, it makes the electron equilibrium distribution functions simpler.2|53|24更新时间：2025-12-08
- 摘要：This paper presents a new diagnosis method of digital system-Fault FunctionMethod. By means of graph theory, the faults detection, the "single fault" location and the multiple faults location as well as the combinational logic and the sequential logic processes are all unified. This method also gives the rule forming the minimal set of tests. The assumption of single fault and fault simulation are both eliminated.2|37|5更新时间：2025-12-08
- 摘要：This article analyses and discusses the design features of an improved emitter feedback data amplifier with excellent technical characteristics. Its temperature drift of input offset voltage is not greater than O. 5μV/℃. The linearity of closed loop gain is not worse than ×0.01%. The common mode rejection ratio reaches 30dB. The closed loop differential mode input resistance is no less than 1000M. The effective low frequency input voltage noise is not larger than 1μV（p-p） in 0-2Hz.These characteristics have been gained through a simply-constructed circuit based on advanced principles. The whole amplifier can be easily divided into several independent sections. As a result, except a few components, it can not only be integrated monolithicly, but also be assembled with multichip integrated circuits. At the same time, it can also be assembled hybridly with discrete components and integrated circuit operational amplifier easily. All these advantages will make this data amplifier the best circuit in the data acquisition system.2|23|3更新时间：2025-12-08
- 摘要：A new kind of variating-polarization circulator on the principle of nonrecip-rocal variating polarization is introduced in this paper. It is magnetized with a quadruploe magnetizing field and its structure is simple and compact; the average power is not less than 400W; and it’s behaviour can be compared with the conventional four-port waveguide circulator. The main part of the variating-polarizator is a section of square waveguide in which four pieces of ferrite are placed on centers of the waveguide walls symmetrically, while a piece of dielectric slab is placed in space of the waveguide diagonally. They all together form a nonreciprocal variating polarizator.2|44|3更新时间：2025-12-08
- 摘要：As an alternative to optical pulse reflection method based on the principle of optical radar, the "photon probe" offers the possibility that the extremely weak echo from a broken point with any poor fracture or certain imperfection can be detected.The "space-separation effect" had been observed in our research and analysed.The display of fault location is digitized with the "external time-base-method" suggested in this paper, thus bringing the accuracy of fault location to the limit of the pulse reflection method.Fracture of a 1345m gradient fiber with a total attenuation of 19.3dB and NA0.21 has been measured.4|19|1更新时间：2025-12-08
- 摘要：Analysis of a transistor delayed injection and transit time device is given in this paper. Its configuration is similar to a conventional transistor with the exception of the addition of a v or π layer （transition region） between collector and base regions and it is operated as a diode. The negative resistance and the noise performances are calculated by means of small signal theory. The large-signal performances are also approximately described. It is shown that output power about one watt as well as fairly high efficiency can be obtained at X-band, whereas the measured noise is about 20dB smaller than that of IMPATT.2|24|0更新时间：2025-12-08
- 摘要：In this paper a method for the fault analysis of nonlinear analog circuits is introduced and the solvability of the fault equation is also discussed.2|69|33更新时间：2025-12-08
- 摘要：Analysis of the principle of velocity ambiguity eliminator used in early instrumentation radar has shown that the smoothing time required is too long. The optimum algorithm used as software in radar system is analysed and it is found possible to reduce the smoothing time. A new hardware design is developed which by use of approximate optimum algorithm has made the smoothing time approaching to the computing time in general computer by software. An improvement is made on hardware design for eliminating velocity ambiguity, in this case the time required is about a fourth as compared with the old designs.2|26|0更新时间：2025-12-08
- 摘要：Certain pratical guidelines and design methods for getting optimal characteristics in frequency multipliers are considered, and one of the frequency multiplying circuits in atomic frequency standards is given. The phase drift at the 90MHz output of the （ × 18） frequency multiplier is measured with a phase drift measurment set-up made during the study. The results show that phase drift Δφ = 14° when the ambient temperature varies from 30℃ to 50℃; Δφ=4.7 when the supply-voltage varies from 20V to 22V. The phase noise in our multiplier is also measured with another multiple-period measurement set-up with single sideband mixing designed by authors. Results show that the fractional frequency error due to phase noise in the multiplier is 1.1×10-12 when the averaging time τ = 1 sec., the fractional error is 3.9×10-13 when the averaging time τ= 10 sec., A simple method of single sideband mixing in the frequency multiplier is observed and explained.2|60|0更新时间：2025-12-08
- 摘要：Theoretical and Experimental results are presented of a new high-resolution single-tube color TV camera system using spectrum interleaving technique. In this system the vertical correlation principle is utilized with color stripe filters inclined to the line scanning direction. The output signals of pick-up tube are electrically separated by a comb filter. As a result, Luminance signals of high resolution and chrominance signals of low resolution are obtained. Finally, experimental results are given of 550TV line horizontal resolution.2|11|0更新时间：2025-12-08
- 摘要：An experiment for. broadening the bandwidth of a ferrite microstrip phase shifter is reported. In order to decrease the insert loss and VSWR, the ratio 4πMs/L should equal to a constant. If a suitable substrate of higher 4πMs is chosen and gap width S is increased, the difference of the phase shift angles φmax-φmin can be decreased. The magnetic substrate with low anistropy field must be selected so as to prevent the insert loss from increasing at low end of the frequency band. It is possible that the bandwidth can be 20% of the central frequency.4|55|5更新时间：2025-12-08
- 摘要：The principle of the non-parametric binary rank detector and its performance are described. A prototype of the digital detector has been designed and tested on the sea surface. The results of the surface tests, given in the paper, have demonstrated the non-parametric performance of the detector. If it is used in noncoherent radar it will increase its capability of detecting targets in a clutter background.2|27|0更新时间：2025-12-08
- 摘要：Transistor blocking is investigated using hyperbolic function. A general expression is obtained showing the effect of interference on the useful output and methods of raising the blocking level are discussed.2|81|2更新时间：2025-12-08
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