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1987 Vol. 9, No. 4
Display Method:
1987, 9(4): 289-298.
Abstract:
A fast convergent series---Chebyshev-Bessel series for representing the radiation integral ofphysical optics is constructed. It can be effectively applied to analyse the radiation fields ofreflector antennas.
A fast convergent series---Chebyshev-Bessel series for representing the radiation integral ofphysical optics is constructed. It can be effectively applied to analyse the radiation fields ofreflector antennas.
1987, 9(4): 299-308.
Abstract:
The normalized cut-off frequencies of Eypq and Expq modes for image waveguide arc investigated by EDC method. A generalized mode chart for image waveguide is given. It is useful for determining the first-order higher mode and single mode region and choosing the operationparameters.
The normalized cut-off frequencies of Eypq and Expq modes for image waveguide arc investigated by EDC method. A generalized mode chart for image waveguide is given. It is useful for determining the first-order higher mode and single mode region and choosing the operationparameters.
1987, 9(4): 309-316.
Abstract:
A method based on the method of lines which discretizes a partial differential equation (PDE) into a system of ordinary differential equations (ODEs) is presented. A difference scheme with an error of O(h4) is introduced and a simple method for determining the general solutions of the ODEs is given. Finally, the least-square approximation is used for improving the accuracy of the numerical results. Some numerical results for rectangular coaxial line, ridge waveguide, and shielded stripline are also given. These results are in good agreement with that published in literatures.
A method based on the method of lines which discretizes a partial differential equation (PDE) into a system of ordinary differential equations (ODEs) is presented. A difference scheme with an error of O(h4) is introduced and a simple method for determining the general solutions of the ODEs is given. Finally, the least-square approximation is used for improving the accuracy of the numerical results. Some numerical results for rectangular coaxial line, ridge waveguide, and shielded stripline are also given. These results are in good agreement with that published in literatures.
1987, 9(4): 317-322.
Abstract:
The conditions for four lower modes existing in an insular dielectric waveguide are given. The parameters which affect the propagation properties Of the insular dielectric waveguide are selected optimally by the improved Orthogonal Array Table (OAT). Then a set of parameters for obtaining wider single mode bandwidth, lower conductor and dielectric loss, and small outer field dispersion is given. The single mode bandwidth of insular dielectric waveguide is compared with that of image waveguide, and the difference is not significant.
The conditions for four lower modes existing in an insular dielectric waveguide are given. The parameters which affect the propagation properties Of the insular dielectric waveguide are selected optimally by the improved Orthogonal Array Table (OAT). Then a set of parameters for obtaining wider single mode bandwidth, lower conductor and dielectric loss, and small outer field dispersion is given. The single mode bandwidth of insular dielectric waveguide is compared with that of image waveguide, and the difference is not significant.
1987, 9(4): 323-334.
Abstract:
In this paper, a new algorithm called incremental matrix algorithm for calculating sensitivities of network functions is presented. By use of this algorithm, both difference and differential sensitivity can be calculated. The algorithm can be used in both passive networks and active networks. This algorithm only involves the calculation of polynomial, it can save computing time. In the appendix, sensitivity formulae for 14 usual network founctions are given.
In this paper, a new algorithm called incremental matrix algorithm for calculating sensitivities of network functions is presented. By use of this algorithm, both difference and differential sensitivity can be calculated. The algorithm can be used in both passive networks and active networks. This algorithm only involves the calculation of polynomial, it can save computing time. In the appendix, sensitivity formulae for 14 usual network founctions are given.
1987, 9(4): 335-347.
Abstract:
A new method of calculating the large-chang sensitivity--hybrid matrix method is proposed. This method, is based on the hybrid matrix equation of the linear m-port network with controlled sources. It can be used for the circuits containing VCVS and CCVS. Eight characteristics of large-change sensitivity are given. They will make the method more perfect and flexible to use.
A new method of calculating the large-chang sensitivity--hybrid matrix method is proposed. This method, is based on the hybrid matrix equation of the linear m-port network with controlled sources. It can be used for the circuits containing VCVS and CCVS. Eight characteristics of large-change sensitivity are given. They will make the method more perfect and flexible to use.
1987, 9(4): 348-358.
Abstract:
The role of calcium oxide in the barium aluminate and that of calcium oxide and scandium oxide both doped in the impregnated barium aluminate cathode are analytically studied. The results indicate that there are common consitituents, i.e. 2BaO CaO Al2O3 and utilizable barium oxide in the emission substances of various impregnated barium-calcium-aluminate cathodes. The calcium oxide in the barium aluminates participates in constituting 2BaOCaOAl2O3. It makes the utilizable barium oxide stable. The scandium oxide doped in the barium-calcium-aluminate 5BaO3CaO2Al2O30.6Sc2O3 compound is supposed to be a carrier for aarium oxide or barium atom which is the electron source, and it plays the role in controlling and roplonishing the electron source. The proposed mechanism has been proved by some experimental data.
The role of calcium oxide in the barium aluminate and that of calcium oxide and scandium oxide both doped in the impregnated barium aluminate cathode are analytically studied. The results indicate that there are common consitituents, i.e. 2BaO CaO Al2O3 and utilizable barium oxide in the emission substances of various impregnated barium-calcium-aluminate cathodes. The calcium oxide in the barium aluminates participates in constituting 2BaOCaOAl2O3. It makes the utilizable barium oxide stable. The scandium oxide doped in the barium-calcium-aluminate 5BaO3CaO2Al2O30.6Sc2O3 compound is supposed to be a carrier for aarium oxide or barium atom which is the electron source, and it plays the role in controlling and roplonishing the electron source. The proposed mechanism has been proved by some experimental data.
1987, 9(4): 359-363.
Abstract:
For this probe, the beam spot diameter of the primary electron beam is 50-100m, the primary beam current is lower than 10-7A, and the energy of the primary electron (Ep) can be varied from 200 eV to 3 keV.By use of this probe, the secondary emission coefficient () versus Eq curve and the secondary emission distribution over the cathode surface can be measured, and the secondary emission image of the cathodes can also be displayed. Finally, the secondary emission of the pure nikel sample and impregnated dispenser cathode are measured.
For this probe, the beam spot diameter of the primary electron beam is 50-100m, the primary beam current is lower than 10-7A, and the energy of the primary electron (Ep) can be varied from 200 eV to 3 keV.By use of this probe, the secondary emission coefficient () versus Eq curve and the secondary emission distribution over the cathode surface can be measured, and the secondary emission image of the cathodes can also be displayed. Finally, the secondary emission of the pure nikel sample and impregnated dispenser cathode are measured.
1987, 9(4): 364-367.
Abstract:
This paper introduces the design and the manufacture of a new type gas discarge gun for the cathode luminescent instrument. It contains the decision of the operating model, the design of the discharge gun and the measurements of the gun performance. The experimental curves of the discharge current versus pressure at various potentials will be of great value to the people who operate the cathode luminescent instrument.
This paper introduces the design and the manufacture of a new type gas discarge gun for the cathode luminescent instrument. It contains the decision of the operating model, the design of the discharge gun and the measurements of the gun performance. The experimental curves of the discharge current versus pressure at various potentials will be of great value to the people who operate the cathode luminescent instrument.
1987, 9(4): 368-370.
Abstract:
Four classes of constant weight codes which can meet the Johnson upper bound and two classes of constant weight codes which are greater than the Graham lower bound are given in this paper.
Four classes of constant weight codes which can meet the Johnson upper bound and two classes of constant weight codes which are greater than the Graham lower bound are given in this paper.
1987, 9(4): 371-374.
Abstract:
It is important that the powermeter errors will exert a tremendous influence on the measuring accuracy of six-port reflector. To estimate this influence is very difficult. In this paper, Monte Carlo simulation analysis is used. As a practical example of X band six-port reflector, it gives a set of computing results and diagrams. With this method it will provide scientific basis for designing six-port reflectors.
It is important that the powermeter errors will exert a tremendous influence on the measuring accuracy of six-port reflector. To estimate this influence is very difficult. In this paper, Monte Carlo simulation analysis is used. As a practical example of X band six-port reflector, it gives a set of computing results and diagrams. With this method it will provide scientific basis for designing six-port reflectors.
1987, 9(4): 375-379.
Abstract:
A microwave polar interferometer using four-probe principle is presented, in which four-probe system is replaced by two T-junction waveguides in series with a tunable phase shifter between them. The interferometer is specially suitable for measuring the parameters of plasma transient process, and has the capability of displaying transmission, reflection, and polar characteristic with the origin of its coordinates at the same time.The experimental photographs of a transient plasma in the daylight lamp are clear at frequencies of 10 GHz and 35GHz.
A microwave polar interferometer using four-probe principle is presented, in which four-probe system is replaced by two T-junction waveguides in series with a tunable phase shifter between them. The interferometer is specially suitable for measuring the parameters of plasma transient process, and has the capability of displaying transmission, reflection, and polar characteristic with the origin of its coordinates at the same time.The experimental photographs of a transient plasma in the daylight lamp are clear at frequencies of 10 GHz and 35GHz.
1987, 9(4): 380-384.
Abstract:
Some new formulas for calculating the far zone field of antenna of any length excited by horizontal electric and magnetic sources on the infinite metallic elliptic and hyperbolic cylinders are presented. As an example, the radiation patterns for a stub on the metallic plane are given and the obtained results are compared with the experimental ones, they are basically coincident.
Some new formulas for calculating the far zone field of antenna of any length excited by horizontal electric and magnetic sources on the infinite metallic elliptic and hyperbolic cylinders are presented. As an example, the radiation patterns for a stub on the metallic plane are given and the obtained results are compared with the experimental ones, they are basically coincident.
