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1981 Vol. 3, No. 2
Display Method:
1981, 3(2): 65-71.
Abstract:
The results of an actual X-band rectangular waveguide phase controlled antenna array are given. Using the antenna array as boundary values of electro-magnetic field, a solution of the field equations is made, and an integral equation of the tangential electric feild function of an unknown aperture is established. Through conversion to matrix methods, numerical results are obtained by using the DJS-6 computer. A sourceless small array containing 115 elements was made. The directional diagram of the array element wasmeasured. Also two magnetic H face waveguide simulators: HIC 14 and HIC 29 were made, and experimental tests were performed. The parameters of the wide angled matching dielectric plate and the mateching foil over the aperture were determined by theoretical calculations and experimental results are quite close to each other. On the 8600--9600 MHz band and 60 scanning spherical cone; the VSWR of input voltage on the antenna is less than 2.
The results of an actual X-band rectangular waveguide phase controlled antenna array are given. Using the antenna array as boundary values of electro-magnetic field, a solution of the field equations is made, and an integral equation of the tangential electric feild function of an unknown aperture is established. Through conversion to matrix methods, numerical results are obtained by using the DJS-6 computer. A sourceless small array containing 115 elements was made. The directional diagram of the array element wasmeasured. Also two magnetic H face waveguide simulators: HIC 14 and HIC 29 were made, and experimental tests were performed. The parameters of the wide angled matching dielectric plate and the mateching foil over the aperture were determined by theoretical calculations and experimental results are quite close to each other. On the 8600--9600 MHz band and 60 scanning spherical cone; the VSWR of input voltage on the antenna is less than 2.
1981, 3(2): 72-79.
Abstract:
A new idea of the complex weighted array antennas in proposed. A generalized weighted factor is given. Also, the general formulae for calculating the element numbers, field patterns, power patterns and array efficiency of the complex weighted array antennas are derived. The application of the complex weighted array antennas will be advantageous to the reduction of costs, improvement of performences and system adaptability.
A new idea of the complex weighted array antennas in proposed. A generalized weighted factor is given. Also, the general formulae for calculating the element numbers, field patterns, power patterns and array efficiency of the complex weighted array antennas are derived. The application of the complex weighted array antennas will be advantageous to the reduction of costs, improvement of performences and system adaptability.
1981, 3(2): 80-88.
Abstract:
In this paper, a gain control loop which operates in synthetic radio telescope is described. The influence of noise on the variation of the gain is discussed in some details ; the gain-lock loop is described; the relation between noise power and variation of gain is derived; the formula for determining the threshold of unlocking is given and the experimental results are displayed in Fig. 6 and Fig. 7. In this paper, the steps taken to decrease the influence of noise are also discussed.
In this paper, a gain control loop which operates in synthetic radio telescope is described. The influence of noise on the variation of the gain is discussed in some details ; the gain-lock loop is described; the relation between noise power and variation of gain is derived; the formula for determining the threshold of unlocking is given and the experimental results are displayed in Fig. 6 and Fig. 7. In this paper, the steps taken to decrease the influence of noise are also discussed.
1981, 3(2): 89-95.
Abstract:
In this paper, the output correlation function of nonlinear systems of zero memory with the property of h(lx) characterized by h(k+p)(lx)=lph(k)(lx) (Where h(k)(lx)=(k)h(lx)/xk,l is a real number) is treated, in case of the gaussian process input with zeromathematical expectation.Based on the above characteristics, an ordinary differential equation is derived from Price theorem. Thus a problem of solving the output correlation function of nonlinear system is turned into a problem of solving an ordinary differential equation. The result show that the output correlation functions of nonlinear system of this kind are of the same form. Different h(lx)'s only exert their influences upon coefficients. From the above condition, the characteristic f(x) of the conventional nonlinear system may be expressed in a family of functions which has the performance as mentioned above. by using the results directly, it is easy to obtain a calculating equation concerning the output correlation function of the conventional nonlinear system.
In this paper, the output correlation function of nonlinear systems of zero memory with the property of h(lx) characterized by h(k+p)(lx)=lph(k)(lx) (Where h(k)(lx)=(k)h(lx)/xk,l is a real number) is treated, in case of the gaussian process input with zeromathematical expectation.Based on the above characteristics, an ordinary differential equation is derived from Price theorem. Thus a problem of solving the output correlation function of nonlinear system is turned into a problem of solving an ordinary differential equation. The result show that the output correlation functions of nonlinear system of this kind are of the same form. Different h(lx)'s only exert their influences upon coefficients. From the above condition, the characteristic f(x) of the conventional nonlinear system may be expressed in a family of functions which has the performance as mentioned above. by using the results directly, it is easy to obtain a calculating equation concerning the output correlation function of the conventional nonlinear system.
1981, 3(2): 96-100.
Abstract:
In this paper, there is discussed a fault diagnosis technique and related method of calculation to determine the position and value of a fault component which happens to be in a b-branches network. This technique based on comparing the fault circuit with the adjoint circuit (which is named to indicate the original circuit in normal state) requires only a few measurements on some of accessible nodes or branches.Three main concepts are discussed in this paper: (1) The discussion about the external mapping of the internal faults; (2) The discussion about the extension of a fault state; (3) The discussion about the approach to proventing chain-fault.
In this paper, there is discussed a fault diagnosis technique and related method of calculation to determine the position and value of a fault component which happens to be in a b-branches network. This technique based on comparing the fault circuit with the adjoint circuit (which is named to indicate the original circuit in normal state) requires only a few measurements on some of accessible nodes or branches.Three main concepts are discussed in this paper: (1) The discussion about the external mapping of the internal faults; (2) The discussion about the extension of a fault state; (3) The discussion about the approach to proventing chain-fault.
1981, 3(2): 101-109.
Abstract:
This paper uses the tape helix model and considers the effects of dielectric, axially conducting shield and wire size on dispersion characteristics for the helix structure with longitudinally conducting vane. The actual dielectric rods are replaced by an equivalent dielectric circle. The formula of dispersion characteristics for this type of helix can be deduced from electromagnetic theory. A comparison with experimental data of references [3, 7] shows that they are very close.When the ratio between shield inner radius R and vane inner radius S is larger than 1.1 and the ratio betwenn vane inner radius S and helix mean radius a is smaller than 1.5, the difference between the theoretical value of the phase velocity and experimental values is within five percent. The general design curves have been calculated by computer. They can be used for the design and calculation of this type of helix structure in actual engineering practice.
This paper uses the tape helix model and considers the effects of dielectric, axially conducting shield and wire size on dispersion characteristics for the helix structure with longitudinally conducting vane. The actual dielectric rods are replaced by an equivalent dielectric circle. The formula of dispersion characteristics for this type of helix can be deduced from electromagnetic theory. A comparison with experimental data of references [3, 7] shows that they are very close.When the ratio between shield inner radius R and vane inner radius S is larger than 1.1 and the ratio betwenn vane inner radius S and helix mean radius a is smaller than 1.5, the difference between the theoretical value of the phase velocity and experimental values is within five percent. The general design curves have been calculated by computer. They can be used for the design and calculation of this type of helix structure in actual engineering practice.
1981, 3(2): 110-117.
Abstract:
This paper presents design, computer analysis and experimental result of laminar flow electron beam with rectangular cross section. The beam is used in a deflection-modulated electron-bombarded semiconductor amplifier. This kind of amplifier is a new device in microwave field developed during the last decade.Owing to employing special correcting lens, laminar flow beam with rectangular cross section of 13 mm2 is obtained. Using correcting lens to obtain rectangular beam of finite width is a useful method.This method may be applied to other fields.
This paper presents design, computer analysis and experimental result of laminar flow electron beam with rectangular cross section. The beam is used in a deflection-modulated electron-bombarded semiconductor amplifier. This kind of amplifier is a new device in microwave field developed during the last decade.Owing to employing special correcting lens, laminar flow beam with rectangular cross section of 13 mm2 is obtained. Using correcting lens to obtain rectangular beam of finite width is a useful method.This method may be applied to other fields.
1981, 3(2): 118-124.
Abstract:
The magnetron injection gun is able to provide a beam of high perveance to be used in high power microwave tubes. But usually this kind of gun is regarded as of the crossed-field type, and has the characteristic high noise found in erossed-field devices. This limits its use.There have been experiments that negated such views. In 1962, a C-band low noise T. W. T. used a magnetron injection gun and obtained a noise figure of 3.1dB. Again in 1965, a S-band forward wave amplifier of medium power obtained a noise figureof 3.5dB. But these devices are all limited to low or medium powers, the cathode length is quite short, i.e. the ratio of cathode length to cathode diameter is quite small. using the magnetron injection gun in a magnetron of high power whether we can obtain small enough noise figure is still a problem needing further investigation. In this paper, a discussion of chief factors that influence the noise of magnetron injection guns in a high power magnetron and adoption of a method of changing the distribution of magnetic field around the cathode in order to reduce noise are made. Experimental results of guns adopting this method are presented.
The magnetron injection gun is able to provide a beam of high perveance to be used in high power microwave tubes. But usually this kind of gun is regarded as of the crossed-field type, and has the characteristic high noise found in erossed-field devices. This limits its use.There have been experiments that negated such views. In 1962, a C-band low noise T. W. T. used a magnetron injection gun and obtained a noise figure of 3.1dB. Again in 1965, a S-band forward wave amplifier of medium power obtained a noise figureof 3.5dB. But these devices are all limited to low or medium powers, the cathode length is quite short, i.e. the ratio of cathode length to cathode diameter is quite small. using the magnetron injection gun in a magnetron of high power whether we can obtain small enough noise figure is still a problem needing further investigation. In this paper, a discussion of chief factors that influence the noise of magnetron injection guns in a high power magnetron and adoption of a method of changing the distribution of magnetic field around the cathode in order to reduce noise are made. Experimental results of guns adopting this method are presented.
1981, 3(2): 125-127.
Abstract:
This paper discusses the characteristic of Ni-Co-W alloy which has high strength, low recrystallization, high resistivity and good processability. In addition, it contains both fast and slow reducing agents. This alloy has been used in the transmitting tube FD-422. The result indicates that it is a good base metal for directly heated Oxide-Coated Cathode.
This paper discusses the characteristic of Ni-Co-W alloy which has high strength, low recrystallization, high resistivity and good processability. In addition, it contains both fast and slow reducing agents. This alloy has been used in the transmitting tube FD-422. The result indicates that it is a good base metal for directly heated Oxide-Coated Cathode.
1981, 3(2): 128-128.
Abstract:
An optically pumped FIE pulse laser is described. The pumping source is a tunable TEA CO2 laser with a grating. The output energy of the TEM00 mode is about 1J at 9P(20) and 9R(22) lines.This laser is of a super-radiant structure. The absorbent cell is made of a quartz tube 2m long and 20 mm ID.FIR laser action has been obtained in both CH3F and D2O. Output energies being 0.5 mJ at 496m and 0.55 mJ at 385m respectively.
An optically pumped FIE pulse laser is described. The pumping source is a tunable TEA CO2 laser with a grating. The output energy of the TEM00 mode is about 1J at 9P(20) and 9R(22) lines.This laser is of a super-radiant structure. The absorbent cell is made of a quartz tube 2m long and 20 mm ID.FIR laser action has been obtained in both CH3F and D2O. Output energies being 0.5 mJ at 496m and 0.55 mJ at 385m respectively.
1981, 3(2): 129-131.
Abstract:
This paper presents a demountable gas-filled gap switch. It has high static breakdown voltage and low inductance. It has been used in a Marx generator to produce a rela-tivistie beam for pumping excimer and CO2 lasers.
This paper presents a demountable gas-filled gap switch. It has high static breakdown voltage and low inductance. It has been used in a Marx generator to produce a rela-tivistie beam for pumping excimer and CO2 lasers.
1981, 3(2): 132-136.
Abstract:
Transmission NBA Ⅲ-Ⅴ compound photocathodes may be designed in some cases. This article gives the design principles, design requirements, design procedure and compositional structure, and then gives an example of designing transmission InxGa(1-x)As photocathode in the 0.4-1.1m wavelength. Finally, some problems which have to be resolved for the transmission Gay In(1-y)AsxP(1-x), photocathode in the 0.4-1.7m wavelength are pointed out.
Transmission NBA Ⅲ-Ⅴ compound photocathodes may be designed in some cases. This article gives the design principles, design requirements, design procedure and compositional structure, and then gives an example of designing transmission InxGa(1-x)As photocathode in the 0.4-1.1m wavelength. Finally, some problems which have to be resolved for the transmission Gay In(1-y)AsxP(1-x), photocathode in the 0.4-1.7m wavelength are pointed out.
