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1981 Vol. 3, No. 1
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1981, 3(1): 1-7.
Abstract:
This paper gives a solution of the characteristic equations of the boundary conditions of the dielectric ring loaded horn. This leads to transformation formulas for the connecting boundary of the dielectric ring loaded waveguide and smooth walled waveguide. Using these formulas, the radiation characteristics of the dielectric ring loaded horn according to the design in reference [1] are found. The calculated values are very close to experimental results.
This paper gives a solution of the characteristic equations of the boundary conditions of the dielectric ring loaded horn. This leads to transformation formulas for the connecting boundary of the dielectric ring loaded waveguide and smooth walled waveguide. Using these formulas, the radiation characteristics of the dielectric ring loaded horn according to the design in reference [1] are found. The calculated values are very close to experimental results.
1981, 3(1): 8-15.
Abstract:
Analysis by the use of equivalent circuit method is made for the five-arm ring, and two ways to improve it are found. The improved method can make the center arm entirely match the ring and isolated ideally from the second pair of side arms, and can make the first pair of side arms perfectly match the ring and both arms ideally isolated from each other. A method of design a five-arm ring power divider having three different power ratios is proposed. Analysis and calculation formulas are given. Theoretical resuls and experimental findings agree quite closely.
Analysis by the use of equivalent circuit method is made for the five-arm ring, and two ways to improve it are found. The improved method can make the center arm entirely match the ring and isolated ideally from the second pair of side arms, and can make the first pair of side arms perfectly match the ring and both arms ideally isolated from each other. A method of design a five-arm ring power divider having three different power ratios is proposed. Analysis and calculation formulas are given. Theoretical resuls and experimental findings agree quite closely.
1981, 3(1): 16-21.
Abstract:
On the basis of the Threshold Decision rule calculations are made of the error probability of detecting phase-modulated binary codes in the system of Pseudo-random code for the measure of distance. The results are compared with results of measurements on the basis of the maximum likehood decision rule. It is pointed out that under similar conditions, results obtained from measurements according to the two rules from the point of view of statistical average differ very little; results obtained from the former differ only by 3dB from the later, even calculations are made according to the longest trapping time.
On the basis of the Threshold Decision rule calculations are made of the error probability of detecting phase-modulated binary codes in the system of Pseudo-random code for the measure of distance. The results are compared with results of measurements on the basis of the maximum likehood decision rule. It is pointed out that under similar conditions, results obtained from measurements according to the two rules from the point of view of statistical average differ very little; results obtained from the former differ only by 3dB from the later, even calculations are made according to the longest trapping time.
1981, 3(1): 22-28.
Abstract:
GaAs-Ga1-x Alx As double heterojunction material was grown by liquid phase epitaxial technique, and small area high radiance light emitting diodes are made. The radiation power is above 100W/sr.cm2, output power of the tail fibre (inner diameter 60m N.A.=0.17) is 200W, and extrapolated life reaches 105 hours. It is already being used in the 1.8km 8.448 Mb/s PCM-120 route optic fibre telephone communication system. Analysis is made on the operational characteristics of the diodes. Factors affecting its proper use and approaches for improvement are discussed.
GaAs-Ga1-x Alx As double heterojunction material was grown by liquid phase epitaxial technique, and small area high radiance light emitting diodes are made. The radiation power is above 100W/sr.cm2, output power of the tail fibre (inner diameter 60m N.A.=0.17) is 200W, and extrapolated life reaches 105 hours. It is already being used in the 1.8km 8.448 Mb/s PCM-120 route optic fibre telephone communication system. Analysis is made on the operational characteristics of the diodes. Factors affecting its proper use and approaches for improvement are discussed.
1981, 3(1): 29-34.
Abstract:
A simple, rapid, directly observable method for examining the supporting rod type attenuator s matching property is discussed. The fundamental principle employed is to measure and work out the relative attenuation distribution curve of the attenuator at microwave frequencies, and then by phase shift method to measure the VSWR S, value as an indication of matching quality of the attenuator in its region of slow variation in attenuation, compare and analyse the obtained curve and the S value in order to determine required form of the curve and slope of the starting section. When these are established, in further examination work on attenuators all one needs to do is just to measure and work out an attenuator's microwave relative attenuation distribution curve to see if it meets the requirement established. By adopting this method, one increases greatly the rapidity of measurement. From experimence, we can say that this method is not only useful in the development research work on TMT, but is useful on a small scale manufacturing of TMT's .
A simple, rapid, directly observable method for examining the supporting rod type attenuator s matching property is discussed. The fundamental principle employed is to measure and work out the relative attenuation distribution curve of the attenuator at microwave frequencies, and then by phase shift method to measure the VSWR S, value as an indication of matching quality of the attenuator in its region of slow variation in attenuation, compare and analyse the obtained curve and the S value in order to determine required form of the curve and slope of the starting section. When these are established, in further examination work on attenuators all one needs to do is just to measure and work out an attenuator's microwave relative attenuation distribution curve to see if it meets the requirement established. By adopting this method, one increases greatly the rapidity of measurement. From experimence, we can say that this method is not only useful in the development research work on TMT, but is useful on a small scale manufacturing of TMT's .
EXPERIMENTAL STUDIES OF CONTINUOUS TUNING AND FREQUENCY PULLING EFFECT IN MULTIAT-MOSPHERE CO2 LASER
1981, 3(1): 35-38.
Abstract:
Experimental studies on the continuous tuning and frequency pulling in a grating tuning multiatmosphere CO2 laser is reported. Agermanium prism beam expanding telescope or a spherical mirror beam expanding telescope is used in the cavity to improving the frequency selectivity of the dispersion cavity and enlarge the beam exposed area of the grating. In this way, we achieve at continuous tuning with nearly no pulling effect in the continuous tuning and the grating is also effectively protected.
Experimental studies on the continuous tuning and frequency pulling in a grating tuning multiatmosphere CO2 laser is reported. Agermanium prism beam expanding telescope or a spherical mirror beam expanding telescope is used in the cavity to improving the frequency selectivity of the dispersion cavity and enlarge the beam exposed area of the grating. In this way, we achieve at continuous tuning with nearly no pulling effect in the continuous tuning and the grating is also effectively protected.
1981, 3(1): 39-44.
Abstract:
An investigation into the radial relativistie electron beam for use as a gas laser pumping source is made. Design and experimental results of a coaxial electron gun for the production of a radial electron beam are given. Also a preliminary discussion of certain characteristics of this kind beam is given. With this kind of electron beam, laser output in the ultraviolet region is obtained successfully.
An investigation into the radial relativistie electron beam for use as a gas laser pumping source is made. Design and experimental results of a coaxial electron gun for the production of a radial electron beam are given. Also a preliminary discussion of certain characteristics of this kind beam is given. With this kind of electron beam, laser output in the ultraviolet region is obtained successfully.
1981, 3(1): 45-48.
Abstract:
A resonator with double-curvature mirror to be used as a resonator for optically-pumped lasers at very high efficiency is proposed. This resonator can be regarded as a combination of a stable-resonator and an unstable-resonator. It is a newtype of resonator which is able to obtain a laser beam of high quality.
A resonator with double-curvature mirror to be used as a resonator for optically-pumped lasers at very high efficiency is proposed. This resonator can be regarded as a combination of a stable-resonator and an unstable-resonator. It is a newtype of resonator which is able to obtain a laser beam of high quality.
1981, 3(1): 49-51.
Abstract:
An investigation of the Ba Sr Tungstate cathode was made. It was found that when the tungstate was prepared at 1050℃ for 2 hours the product was stable in the atmosphere, and storing in air with relative humidity of below 70% for 200 hours, its increase in weight was only 0.2%. Cathodes made this way have a reasonably long life.
An investigation of the Ba Sr Tungstate cathode was made. It was found that when the tungstate was prepared at 1050℃ for 2 hours the product was stable in the atmosphere, and storing in air with relative humidity of below 70% for 200 hours, its increase in weight was only 0.2%. Cathodes made this way have a reasonably long life.
1981, 3(1): 52-58.
Abstract:
When an input signal is a non-periodic triangular pulse, an analysis is made of the relation between the input and the output signals. On the basis of the analysis, calculations are made of the trapping time, trapping error and attenuation of the output signal.The non-linear characteristic of the diode is considered according to two different conditions, in the case where the volt-ampere characteristic can be represented in exponential form. The author proposes an iteration form to solve the intermediate region of the two conditions.
When an input signal is a non-periodic triangular pulse, an analysis is made of the relation between the input and the output signals. On the basis of the analysis, calculations are made of the trapping time, trapping error and attenuation of the output signal.The non-linear characteristic of the diode is considered according to two different conditions, in the case where the volt-ampere characteristic can be represented in exponential form. The author proposes an iteration form to solve the intermediate region of the two conditions.
1981, 3(1): 59-61.
Abstract:
Noise sources of the junction type PET and formulas for them are presented. These are practical formulas for common source, common grid and common drain for the PET in low, medium and high frequency regions, they being obtained by use of the Y admittance model. Also, a comparison is made of noise characteristics of the three configurations of the FET, from which certain principles in low noise design are suggested.
Noise sources of the junction type PET and formulas for them are presented. These are practical formulas for common source, common grid and common drain for the PET in low, medium and high frequency regions, they being obtained by use of the Y admittance model. Also, a comparison is made of noise characteristics of the three configurations of the FET, from which certain principles in low noise design are suggested.
1981, 3(1): 62-64.
Abstract:
After comparing many types of antennas, we decided on the corrugated horn feed cassegrainian antenna. After improvement in input feeding method, the antenna becomes usable. After many flying tests, it proves rugged enough. For X-band, the characteristics of the antenna are: diameter D=800 mm, Gain G=34.7 dB, Side lode 2%, beam width 20.5=247 .
After comparing many types of antennas, we decided on the corrugated horn feed cassegrainian antenna. After improvement in input feeding method, the antenna becomes usable. After many flying tests, it proves rugged enough. For X-band, the characteristics of the antenna are: diameter D=800 mm, Gain G=34.7 dB, Side lode 2%, beam width 20.5=247 .
