1992 Vol.14 No.6, Published: 19 November 1992
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Articles |
Zhang Delong
RESEARCH OF CONTROLLABLE ARTIFICIAL DELAY LINE
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1992 Vol. 14 (6): 561-566
[Abstract]
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1801 )
[PDF 1009KB]
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837
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DOI:
An artificial delay line which was designed by using the DYL integrated linear AND-OR gate created first in China were proposed. This kind of delay circuit has not only the advantages of simpler structure, more rapid velocity for signal trasmission, but also the circuit delay which can be controlled by digital quantity.
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Yang Jun①;Fan Changxin②
NONLINEAR COCHLEAR MECHANICAL MODEL AND ITS BIAS TECHNIQUE
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1992 Vol. 14 (6): 567-573
[Abstract]
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1464 )
[PDF 1123KB]
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634
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DOI:
The nonlinear equation modeling the 2-D cochlear mechanics is established,and an effective method-bias technique for computing this equation is presented. The modelshows many effects which correlate closely to physiological counterparts. The quantitative data on the level-dependence of frequency responses are given.
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Tian Zhiren; Tan Wei
A DESIGNING MODEL OF ACTIVE MATRIX FOR LIQUID-CRYSTAL DISPLAYS
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1992 Vol. 14 (6): 579-587
[Abstract]
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1438 )
[PDF 1417KB]
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658
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DOI:
A designing model of active matrix for liquid-crystal displays (LCDs) is developed. It consists of a total designing idea of active matrix, the characteristics of ac ive matrix devices and the physics of liquid crystal cell capacitance being charged or discharged. Some factors influencing the characteristics of active matrix are also considered. Based on the analysis, the calculating formulas for the design are deduced. Some proposals for optimizing the design of active matrix for LCDs are offered|.
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Yang Yixian
A NEW METHOD FOR THE DESIGN OF FULL FREQUENCYHOP CODES
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1992 Vol. 14 (6): 588-595
[Abstract]
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1432 )
[PDF 1855KB]
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527
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DOI:
Permutation polynomials in finite fields are initially introduced into the design of full frequency hop codes. Various kinds of full frequency hop codes with ideal au-to-and cross-ambiguity functions are presented in this paper. For example, the codes of class 2 are the best full frequency hop codes up to now.
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Lu Peizhong; Song Guowen
ON JUSTESENS ALGEBRAIC GEOMETRY CODES
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1992 Vol. 14 (6): 602-610
[Abstract]
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1429 )
[PDF 1447KB]
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827
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DOI:
An isomorphism preserving Hamming weight between two algebraic geometry (AG) codes is presented to obtain the main parameters of Justesen s algebraic geometry (JAG) codes. To deduce a simple approach to the decoding algorithm, a code word in a "small" JAG code is used to correspond to error-locator polynomial. By this means, a simple decoding procedure and the ability of error correcting are explored obviously. The low and up bounds of the dimension of AG codes are also obtained.
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Feng Lin; Lu Congxiao
A NEW TYPE OF WIDE-BAND RADAR ABSORBING COATING
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1992 Vol. 14 (6): 618-623
[Abstract]
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1433 )
[PDF 1114KB]
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918
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DOI:
A new type of absorbing coaing which is formed by inserting a frequency selective surface in an ordinary coating, is introduced. The absorbing properties of the new coating are given and compared with those of the ordinary absorbing coating.
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Wang Yinjuan; Yang Linyao; Wu Dazheng
A NEW APPROACH FOR DESIGN CENTERING BASED ON STOCHASTIC APPROXIMATION
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1992 Vol. 14 (6): 624-628
[Abstract]
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1527 )
[PDF 801KB]
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691
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DOI:
A new optimization technique which combines one dimension exploration with stochastic approximation is presented. A quadratic model is used to approximate the response of a circuit over a parameter space. The circuit yield for different design center values is estimated using correlated sampling and quadratic model via Monte Carlo method. An example shows that the convergence of this approach is faster and required CPU-time is less.
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Dai Yongsheng
A NOVEL Ku-BAND LOW NOISE AMPLIFIER WITH HEMT AND GaAs MMIC
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1992 Vol. 14 (6): 629-632
[Abstract]
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1728 )
[PDF 682KB]
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1034
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DOI:
A novel Ku-band low noise amplifier with high electron mobility transis-ror (HEMT) and GaAs monolithic microwave integrated circuit (MMIC) has been demonstrated. Its noise figure is less than 1.9dB with an associated gain over 27dB and an input-output VSWR less than 1.4 in the frequency range of 11.7-12.2 GHz. The HEMT and the microwave series inductance feedback technique arc used in the first stage of the amplifier, and the Ku-band MMIC is used in the last stage. The key to this design is to achieve a simultaneous optimum noise match and a minimum input VSWR match by using the microwave series inductance feedback method. The BJ-120 waveguides are used in both input and output of the amplifier.
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Wu Jie; Hong Yi
SWITCHED-C URRENT FILTER DESIGN USING CASCADED SECTIONS
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1992 Vol. 14 (6): 633-638
[Abstract]
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1795 )
[PDF 886KB]
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623
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DOI:
A new analogue sampled-data active device, called as a switched-current operational amplifier (SIOA), is presented. The use of the active element may simplify drawing the circuit diagram greatly and may permit easier analysis and synthesis of SI networks. A number of all pole and elliptic (second or third order) switched current (SI) circuits are derived from the switched capacitor prototypes. These can be used as simple self-contained filters or as filter sections in the cascade realizations of a higher order transfer functions. To illustrate the design approach, a fifth-order lowpass filter is presented.
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Song Bin; Fu Junmei
COMPUTATION OF HIGHER-ORDER MODE CUT-OFF FREQUENCIES IN TEM CELLS USING BOUNDARY-ELEMENT METHOD
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1992 Vol. 14 (6): 648-651
[Abstract]
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1777 )
[PDF 630KB]
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577
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DOI:
The boundary-element method is proposed to investigate the higher-order mode cut-off frequencies in TEM cells. Both TE and TM modes are considered. For symmetry, only one quarter of the cross-section is analyzed, and electric aad magnetic walls are employed in the cross-section. With this method, mode identification can easily be made by using an eigenvector solution. The obtained results are compared with data available in literatures.
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Chen Li; Pan Jin
EM SCATTERING BY RECTANGULAR CONDUCTING PLATE COATED WITH LOSSY DIELECTRIC
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1992 Vol. 14 (6): 652-656
[Abstract]
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1487 )
[PDF 868KB]
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651
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DOI:
The EM scattering by rectangular conducting flat plate coated with lossy dielectric, whose parameters may be arbitrary, is studied To avoid the complex integral, Ma-liuzhinets functions involved are approximated with close-form analytical expressions so that the computing time is reduced greatly. The results in the paper are in fair agreement with the experimental ones.
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Liu Luokun; Sun Guangxiang
DESIGN OF CIRCULAR-RECTANGULAR WAVEGUIDE TRANSITION DEVICE
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1992 Vol. 14 (6): 657-660
[Abstract]
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1680 )
[PDF 547KB]
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622
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DOI:
The variation equation and numerical result for the cut-off wavelength of the truncated circular waveguide are given byusing the variational principle and Rayleigh-Ritz variational technique, and choosing a proper ba se function. A good performance circular-rectangular waveguide staircase transition device is designed.
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Wei Yayi
STUDY OF THE SURFACE STRUCTURE OF LEAD SILICATE GLASS REDUCED BY HYDROGEN
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1992 Vol. 14 (6): 661-665
[Abstract]
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2104 )
[PDF 802KB]
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713
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DOI:
The XPS, AES and EP have been used to study the elemental depth-distributions of secondary eletron emission layer of lead silicate glass reduced by hydrogen. The samples treated at different temperatures have differences in their micro-structures. The effects of different reduced temperature have been discussed, and new model of the layer of secondary electron emitter has been suggested
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Reviews |
Xiong Yuanxin;Ma Chengzhang
THE GROUP CHARACTERS OF GYRATORS AND IDEAL TRANSFORMERS
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1992 Vol. 14 (6): 639-642
[Abstract]
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1856 )
[PDF 599KB]
(
601
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DOI:
The set GIT (2) of all gyrators and ideal transformers is studied by the method of group theory in this paper. The results show that the set GIT (2) forms a group, and it is a subgroup of GL(2). The inner structure of GIT (2), which shows the relations between gyrators and ideal transformers, is also studied. Finally, the properties of the direct productnetwork of two-port network is analysed.
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