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1983 Vol. 5, No. 4
Display Method:
1983, 5(4): 201-209.
Abstract:
The design considerations of the microstrip array, the analytical espressions of the microstrip antenna (element), the approximate admittance formula of input admittance, and two designed antenna arrays are given in this paper. Eather good results have been obtained of the main performances of the designed antenna arrays, such as sidelobe Ievel, VSWR, cross polarization level, and gain etc.
The design considerations of the microstrip array, the analytical espressions of the microstrip antenna (element), the approximate admittance formula of input admittance, and two designed antenna arrays are given in this paper. Eather good results have been obtained of the main performances of the designed antenna arrays, such as sidelobe Ievel, VSWR, cross polarization level, and gain etc.
1983, 5(4): 210-213.
Abstract:
A complementary partitive graph is a bipartite graph G(V , V; E) with disjoint vertex sets V , V, and an edge set E such that all edges are directed except only one edge, say j=[x, y], is undireeted, and the outgoing degrees are d+(x)=0, d+(y)=0 and d+(v)=1 for all vx, y. The following assertions can be easily proved: If G(v' , V; E) is a complementary partitive graph with undireeted edge j, then a pair of eomple mentary partitions P' (E) and P(E) with respect to j can be constructed by the edges incident with each vertex of V' and each vertex of V'' . Conversely, if Hk has a complementary partition with respect to j, then a complementary partitive graph can be constructed. by using the complementary partiive graph defined above. We can ease the proofs of theorems of complementary partitions established by W. K. chen (1969, 1976) and give a simple criterion to determine whether or not a complementary partition is essential as follows: Theorem A complementary partition is essential if and only if the corresponding complementary partitive graph is a connected graph.
A complementary partitive graph is a bipartite graph G(V , V; E) with disjoint vertex sets V , V, and an edge set E such that all edges are directed except only one edge, say j=[x, y], is undireeted, and the outgoing degrees are d+(x)=0, d+(y)=0 and d+(v)=1 for all vx, y. The following assertions can be easily proved: If G(v' , V; E) is a complementary partitive graph with undireeted edge j, then a pair of eomple mentary partitions P' (E) and P(E) with respect to j can be constructed by the edges incident with each vertex of V' and each vertex of V'' . Conversely, if Hk has a complementary partition with respect to j, then a complementary partitive graph can be constructed. by using the complementary partiive graph defined above. We can ease the proofs of theorems of complementary partitions established by W. K. chen (1969, 1976) and give a simple criterion to determine whether or not a complementary partition is essential as follows: Theorem A complementary partition is essential if and only if the corresponding complementary partitive graph is a connected graph.
1983, 5(4): 214-220.
Abstract:
The impulse response sequence of min imum peak sidelobe filter (LP filter) for m-sequence phase-coded waveform can be f ound by using linear programming method. The results of computation for all the 15-element and 31-element m-sequences show that the LP filters can significantly suppress the peak sidelobes. Por the 15-element code with feedback connection [4, 3, 0] and initial condition 1001, the peak sidelobe Ievel is reduced to - 21.47 dB by using LP filter of length 15, and it is 7.49 dB better than that by using matched filter. For the 31-element code with feedback connection [5,3,2,1] and initial condition 11101, the peak sidelobe level is reduced to -23.80 dB by suing LP filter of length 31, and it is 6.01 dB better than that by using matched filter. The LP filter can suppress the peak sidelobe even more when its length is increased.
The impulse response sequence of min imum peak sidelobe filter (LP filter) for m-sequence phase-coded waveform can be f ound by using linear programming method. The results of computation for all the 15-element and 31-element m-sequences show that the LP filters can significantly suppress the peak sidelobes. Por the 15-element code with feedback connection [4, 3, 0] and initial condition 1001, the peak sidelobe Ievel is reduced to - 21.47 dB by using LP filter of length 15, and it is 7.49 dB better than that by using matched filter. For the 31-element code with feedback connection [5,3,2,1] and initial condition 11101, the peak sidelobe level is reduced to -23.80 dB by suing LP filter of length 31, and it is 6.01 dB better than that by using matched filter. The LP filter can suppress the peak sidelobe even more when its length is increased.
1983, 5(4): 221-227.
Abstract:
In this report the diffusion of Zn into GaAs at low temperature has been investigated. The experiments are accomplished in an evacuated and sealed quartz ampoule using ZnAs2 as the source of Zn.The relation among the junction depth (Xj), the time (t) and the temperature (T) of diffusion has been investigated. It is found that the sheet resistance (Rs) of diffu-sion layer increases as the junetion depth (Xj) decreases, the surface concentration (C2) decreases as 1/T increases and the carrier mobility () decreases as Cs increases. The Cs vs. 1/XjRs is plotted, it indicates that the Cs increases as 1/(XjRs) inereases. This is a simple method for determining the Cs of the multiple Ga1-xAlxAs/GaAs epitaxial layer. The mechanism of Zn diffusion in GaAs and InP is discussed. This process has been applied to fabricate GaAlAs/GaAs double heterojunction light emitting idodes and an output power of 2-4 mW and a series resistance of 3-5 are obtained.
In this report the diffusion of Zn into GaAs at low temperature has been investigated. The experiments are accomplished in an evacuated and sealed quartz ampoule using ZnAs2 as the source of Zn.The relation among the junction depth (Xj), the time (t) and the temperature (T) of diffusion has been investigated. It is found that the sheet resistance (Rs) of diffu-sion layer increases as the junetion depth (Xj) decreases, the surface concentration (C2) decreases as 1/T increases and the carrier mobility () decreases as Cs increases. The Cs vs. 1/XjRs is plotted, it indicates that the Cs increases as 1/(XjRs) inereases. This is a simple method for determining the Cs of the multiple Ga1-xAlxAs/GaAs epitaxial layer. The mechanism of Zn diffusion in GaAs and InP is discussed. This process has been applied to fabricate GaAlAs/GaAs double heterojunction light emitting idodes and an output power of 2-4 mW and a series resistance of 3-5 are obtained.
1983, 5(4): 228-237.
Abstract:
This paper describes the series and parallel rectifier technology of the silicon cells.
This paper describes the series and parallel rectifier technology of the silicon cells.
1983, 5(4): 238-246.
Abstract:
In this paper, we present a single period, one dimensional time integral model, with which we can calculate the energy exchange between the rf field and electrons in the output section of a klystron. We give a method by which the distance integral can be transformed simply into the time integral and the calculation of the space charge force of electron disks in the output section can be resolved.We write a program with DJS-6 type computer automation language, with which we calculate a C-band broadband klystron. It shows that the calculated resultsand the experimental ones are in good agreement. We also study the influence of the parameters of output section on the efficiency of the klystron.
In this paper, we present a single period, one dimensional time integral model, with which we can calculate the energy exchange between the rf field and electrons in the output section of a klystron. We give a method by which the distance integral can be transformed simply into the time integral and the calculation of the space charge force of electron disks in the output section can be resolved.We write a program with DJS-6 type computer automation language, with which we calculate a C-band broadband klystron. It shows that the calculated resultsand the experimental ones are in good agreement. We also study the influence of the parameters of output section on the efficiency of the klystron.
1983, 5(4): 247-258.
Abstract:
This paper investigates the influence of transverse and axial momentum spreads on Electron Cyclotron Resonance Maser (ECEM), and gives the general expression of the perturbed distribution function and the dispersion equation for the interaction between TEmn,l mode and electron beam.As two special examples, when △p0 and △pz0 or m = 0 the results of this paper are identical with related references.
This paper investigates the influence of transverse and axial momentum spreads on Electron Cyclotron Resonance Maser (ECEM), and gives the general expression of the perturbed distribution function and the dispersion equation for the interaction between TEmn,l mode and electron beam.As two special examples, when △p0 and △pz0 or m = 0 the results of this paper are identical with related references.
1983, 5(4): 259-264.
Abstract:
In this paper, the structure, the conditions of operation and the performances of a cesium ion source have been described. And the mass-spectrums of residual gases du-ring operation have been shown. The erperimantal results sho,w that there are some advantages of this cesium ion source, such as having a simple structure, easy to operate, well directed, and giving a reproducible yi eld for practical uses. It is a practical cesium ion source with good directivity.
In this paper, the structure, the conditions of operation and the performances of a cesium ion source have been described. And the mass-spectrums of residual gases du-ring operation have been shown. The erperimantal results sho,w that there are some advantages of this cesium ion source, such as having a simple structure, easy to operate, well directed, and giving a reproducible yi eld for practical uses. It is a practical cesium ion source with good directivity.
