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1983 Vol. 5, No. 2
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1983, 5(2): 69-76.
Abstract:
In this paper the effects of Doppler shift error on the imaging of synthetic aperture radar are analysed. The calculating formulae, the experimental methods, the experimetal results, and the error analysis of optical compensation to eliminate the effects are given.
In this paper the effects of Doppler shift error on the imaging of synthetic aperture radar are analysed. The calculating formulae, the experimental methods, the experimetal results, and the error analysis of optical compensation to eliminate the effects are given.
1983, 5(2): 77-83.
Abstract:
Using a planar optical waveguide electro-optic modulator and simple double beam interfering device, the experimental study of optical bistability and multistability is succesfully performed. The waveguide modulator is made by depositing Aluminium as electrodes on the Ti-diffused LiNbO3 planar optical waveguide which is fabricated by ourselves. Laser beam is coupled directly into the end of optical waveguide modulator and out of the Bi12GeO20 prism. Optical rotation arising from Bi12GeO21 crystal is overcome in experiment. In addition to analyzing and discussing optical bistability the multistabilitical hysteresis curves of different shapes obtained in experiments are particularly investigated.
Using a planar optical waveguide electro-optic modulator and simple double beam interfering device, the experimental study of optical bistability and multistability is succesfully performed. The waveguide modulator is made by depositing Aluminium as electrodes on the Ti-diffused LiNbO3 planar optical waveguide which is fabricated by ourselves. Laser beam is coupled directly into the end of optical waveguide modulator and out of the Bi12GeO20 prism. Optical rotation arising from Bi12GeO21 crystal is overcome in experiment. In addition to analyzing and discussing optical bistability the multistabilitical hysteresis curves of different shapes obtained in experiments are particularly investigated.
1983, 5(2): 84-90.
Abstract:
Two methods, manual backing off and capacitor coupling (by cutting off the d.c. component) are usually used to measure a small transient signal superposed on a large electric current. The shortcomings of them are analysed and an automatic current backing off circuit with high accuracy is described in this paper. The response time of this circuit needed for the compensating a sudden change in the large electric current is less than 50 microseconds. The described circuit can be used for the time scale from 1....
Two methods, manual backing off and capacitor coupling (by cutting off the d.c. component) are usually used to measure a small transient signal superposed on a large electric current. The shortcomings of them are analysed and an automatic current backing off circuit with high accuracy is described in this paper. The response time of this circuit needed for the compensating a sudden change in the large electric current is less than 50 microseconds. The described circuit can be used for the time scale from 1....
1983, 5(2): 91-94.
Abstract:
In this paper, for linear discrete-time systems under uncertain observations, the recursive formulas for linear least mean-square error (LMSE) filter and one-step predictor is derived, when they exist.
In this paper, for linear discrete-time systems under uncertain observations, the recursive formulas for linear least mean-square error (LMSE) filter and one-step predictor is derived, when they exist.
1983, 5(2): 95-99.
Abstract:
In this report the diffusion of Zn in InP at low temperature is investigated. The experiment is accomplished in an evacuated and sealed quartz ampoule using Zn3P2 as the source of Zn.The electrical characteristics of the samples obtained by the isotemperature process and the two-temperature process are compared. It is found that the two-temperature process may obtain a smooth, no damage and high-concentration surface layer. This process has been applied to fabricate InGaAsP/InP light emitting diodes, and the diodes obtained have an output power of about 1mW with a series resistance of 23. the behaviors of Zn diffusion in InP are discussed, and the anomalous phenomena in isotemperature diffusion at 550℃ are explained.
In this report the diffusion of Zn in InP at low temperature is investigated. The experiment is accomplished in an evacuated and sealed quartz ampoule using Zn3P2 as the source of Zn.The electrical characteristics of the samples obtained by the isotemperature process and the two-temperature process are compared. It is found that the two-temperature process may obtain a smooth, no damage and high-concentration surface layer. This process has been applied to fabricate InGaAsP/InP light emitting diodes, and the diodes obtained have an output power of about 1mW with a series resistance of 23. the behaviors of Zn diffusion in InP are discussed, and the anomalous phenomena in isotemperature diffusion at 550℃ are explained.
1983, 5(2): 100-107.
Abstract:
The coupling coefficient between circular-electric modes H○01 and H◎01 through a spiral line in circular waveguide is calculated. Certain corrections to S. E. Miller s design of a H○01H○02mode transducer are made. More complete design formulas are given. Agreement between experimental results and our theoretical calculations is attained. In the frequency range from 32 to 37.5 GHz, the conversion loss is less than 0.6 dB, the amplitude of unwanted mode (H○01) less than15 dB and the V. S. W. E less than 1.2.
The coupling coefficient between circular-electric modes H○01 and H◎01 through a spiral line in circular waveguide is calculated. Certain corrections to S. E. Miller s design of a H○01H○02mode transducer are made. More complete design formulas are given. Agreement between experimental results and our theoretical calculations is attained. In the frequency range from 32 to 37.5 GHz, the conversion loss is less than 0.6 dB, the amplitude of unwanted mode (H○01) less than15 dB and the V. S. W. E less than 1.2.
1983, 5(2): 108-115.
Abstract:
In this paper, electron motion in the adiabatic magnetron injection gun (AMIG) of Gyrotron is briefly described. A concept of equivalent diode operating with temperature limited emission in the cathode region is proposed. A formula calculating transverse beam energy determined by the electrode dimensions and electromagnetic parameters is derived from the adiabatic theory and the analysis of electron stream in this diode and the field between two concentric cylinders. With this formula, it is very convenient for us to rapidly and correctly determine the main parameters of the AMIG or judge the moving condition of the electron beam in Gyrotron according to practical parameters. The comparison between the calculations of the cathode field in this paper and the mumerical results of the AMIG given by computer shows that the difference is within five percent, and the former also coincide with the computed data from reference[1]. The calculations of transverse beam energy are in good agreement with experimental results.
In this paper, electron motion in the adiabatic magnetron injection gun (AMIG) of Gyrotron is briefly described. A concept of equivalent diode operating with temperature limited emission in the cathode region is proposed. A formula calculating transverse beam energy determined by the electrode dimensions and electromagnetic parameters is derived from the adiabatic theory and the analysis of electron stream in this diode and the field between two concentric cylinders. With this formula, it is very convenient for us to rapidly and correctly determine the main parameters of the AMIG or judge the moving condition of the electron beam in Gyrotron according to practical parameters. The comparison between the calculations of the cathode field in this paper and the mumerical results of the AMIG given by computer shows that the difference is within five percent, and the former also coincide with the computed data from reference[1]. The calculations of transverse beam energy are in good agreement with experimental results.
1983, 5(2): 116-123.
Abstract:
A non-intercepting gridded gun with the perveance of 1.4p is described. Three different grid-mesh shapes (square, hexagonal and annular) are chosen, and the experimental results in an electron beam analyzer are given in detail. The design methods of the gun for each grid-mesh shape and the structures of the test system are briefly introduced. The results measured by using the fluorescent screen and pin-hole scanning technique are given. It turns out that the annular grid possessed the best electron optical performance. The reason that the performance of the annular grid is better than the others is qualitatively explained and discussed, so as to give the guide lines of how to design the non-intercepting gridded guns. Through the experiment and computer calculation for several non-intercepting gridded guns, the previous wrong conceptional conclusions about the performances of the guns with and without grid may be corrected.
A non-intercepting gridded gun with the perveance of 1.4p is described. Three different grid-mesh shapes (square, hexagonal and annular) are chosen, and the experimental results in an electron beam analyzer are given in detail. The design methods of the gun for each grid-mesh shape and the structures of the test system are briefly introduced. The results measured by using the fluorescent screen and pin-hole scanning technique are given. It turns out that the annular grid possessed the best electron optical performance. The reason that the performance of the annular grid is better than the others is qualitatively explained and discussed, so as to give the guide lines of how to design the non-intercepting gridded guns. Through the experiment and computer calculation for several non-intercepting gridded guns, the previous wrong conceptional conclusions about the performances of the guns with and without grid may be corrected.
1983, 5(2): 124-129.
Abstract:
In this paper, a double arm charge-discharge circuit is described. A high repetition-rate high voltage and variable width rectangular pulse has been obtained. Its technical data are as follows: Its amplitude is 600 V-8 kV continuously adjustable; The maximum repetition-rate is 30kHz; The rise and fall time is less then 1.5s when the load capacity is 56 pF, less then 1.8s when the load capacity is 112 pF; The pulse duration ratio is 1:10-1:1 continuously adjustable. Theoretical analysis for the circuit, has been made.
In this paper, a double arm charge-discharge circuit is described. A high repetition-rate high voltage and variable width rectangular pulse has been obtained. Its technical data are as follows: Its amplitude is 600 V-8 kV continuously adjustable; The maximum repetition-rate is 30kHz; The rise and fall time is less then 1.5s when the load capacity is 56 pF, less then 1.8s when the load capacity is 112 pF; The pulse duration ratio is 1:10-1:1 continuously adjustable. Theoretical analysis for the circuit, has been made.
1983, 5(2): 130-132.
Abstract:
This paper describes the functions of both the toroidal alignment coil and the centering deflection plates in the sealed light valve tube. If the electrode sizes, the spaces between electrodes and the electron beam transparency are known, the spot size and the aligning tolerance between the electron gun and DFS(deflection focus system) can be evaluated.
This paper describes the functions of both the toroidal alignment coil and the centering deflection plates in the sealed light valve tube. If the electrode sizes, the spaces between electrodes and the electron beam transparency are known, the spot size and the aligning tolerance between the electron gun and DFS(deflection focus system) can be evaluated.
1983, 5(2): 133-136.
Abstract:
In this paper, the influence of geometric dimensions of the thick window-body with two quartz discharge tubes on the characterstic of resonant frequency and bandwidth are investigated experimentally. The thick window-body with quartz discharge tubes can be used as dual TR tube or in the dual TR tube.
In this paper, the influence of geometric dimensions of the thick window-body with two quartz discharge tubes on the characterstic of resonant frequency and bandwidth are investigated experimentally. The thick window-body with quartz discharge tubes can be used as dual TR tube or in the dual TR tube.
