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1988 Vol. 10, No. 1
Display Method:
1988, 10(1): 1-7.
Abstract:
A new consrained eigenvalue method for scattering parameters measurements of two-port lossless reciprocal network is developed. The non-linear S-curve problem is easily transformed into a simple linear one by this method. The formulas are programmed on the IBM-PC digital computer. Some examples are given.
A new consrained eigenvalue method for scattering parameters measurements of two-port lossless reciprocal network is developed. The non-linear S-curve problem is easily transformed into a simple linear one by this method. The formulas are programmed on the IBM-PC digital computer. Some examples are given.
1988, 10(1): 8-16.
Abstract:
A loop charge approach is presented for the exact analysis of switched-capacitor networks containing capacitors, independent voltage sources, switches and nullors. t allows for arbitrary K-phase switching situations. And both arbitrary continuous time and liscrete time inputs are handled. By. means, of loop charge approach, exact formulations of apacitor voltages are derived in terms of the input voltages.
A loop charge approach is presented for the exact analysis of switched-capacitor networks containing capacitors, independent voltage sources, switches and nullors. t allows for arbitrary K-phase switching situations. And both arbitrary continuous time and liscrete time inputs are handled. By. means, of loop charge approach, exact formulations of apacitor voltages are derived in terms of the input voltages.
1988, 10(1): 17-24.
Abstract:
In this paper, the eigenvalue problems of multilayer dielectric waveguide consisting of arbitrary number of layers are solved by microwave network method. A general program with the function of computer graphics has been made for analyzing the dispersion characteristics and the electromagnetic field distribution of N layer dielectic waveguide. As an example of practical applications, the procedure of mode conversion and separation in delectric branching waveguide is vividly demostrated through analyzing the field distribution of asymmetric dielectic structure and the general rules of mode conversion are discussed.
In this paper, the eigenvalue problems of multilayer dielectric waveguide consisting of arbitrary number of layers are solved by microwave network method. A general program with the function of computer graphics has been made for analyzing the dispersion characteristics and the electromagnetic field distribution of N layer dielectic waveguide. As an example of practical applications, the procedure of mode conversion and separation in delectric branching waveguide is vividly demostrated through analyzing the field distribution of asymmetric dielectic structure and the general rules of mode conversion are discussed.
1988, 10(1): 25-34.
Abstract:
Numerical results of the aperture field, pattern and directivity of a stripline planar antenna element are obtained by use of the moment method. The difficulty of singularities in integral equation is overcome by a simple shift of the testing functions.
Numerical results of the aperture field, pattern and directivity of a stripline planar antenna element are obtained by use of the moment method. The difficulty of singularities in integral equation is overcome by a simple shift of the testing functions.
1988, 10(1): 35-41.
Abstract:
A large signal self-consistent solution of orotron for a simplified model is given. In this model the electron beam is modulated by the field and the field is excited by the electron beam inversely. A parameter Zc, which is very important for the efficiency (as well as for getting oscillation), is deduced. By means of this simplified model calculation is carried out for some practical parameters of orotron. It is shown that for producing a practical orotroa in wide frequency range, it is necessary to design a quasi-optical resonator not only with a high QH but also with a wide and long enough mode spot on the grating. And for the electron beam, a very small thickness is needed and it ought to pass by the grating as closely as possible, and a high enough value of current is also very necessary.
A large signal self-consistent solution of orotron for a simplified model is given. In this model the electron beam is modulated by the field and the field is excited by the electron beam inversely. A parameter Zc, which is very important for the efficiency (as well as for getting oscillation), is deduced. By means of this simplified model calculation is carried out for some practical parameters of orotron. It is shown that for producing a practical orotroa in wide frequency range, it is necessary to design a quasi-optical resonator not only with a high QH but also with a wide and long enough mode spot on the grating. And for the electron beam, a very small thickness is needed and it ought to pass by the grating as closely as possible, and a high enough value of current is also very necessary.
STUDY OF GYROMONOTRON WITH A COMPOSITE PERIODIC MAGNETIC FIELD AND A COAXIAL CYCLOTRON ELECTRON BEAM
1988, 10(1): 42-52.
Abstract:
On the base of the works of the author (1985) and Liu Shenggang (1985), by using the linear kinetic theory, the gyromontron operating with a composite periodic magnetic field and a coaxial cyclotron rlectron beam is analysed in detail. The equations for the power interaction between electron beam and wave, the frequency shift and the starting oscillation curent are given.
On the base of the works of the author (1985) and Liu Shenggang (1985), by using the linear kinetic theory, the gyromontron operating with a composite periodic magnetic field and a coaxial cyclotron rlectron beam is analysed in detail. The equations for the power interaction between electron beam and wave, the frequency shift and the starting oscillation curent are given.
1988, 10(1): 53-64.
Abstract:
The effects of the beam thickness and the conducting wall in a free electron laser with a linearly polarized wiggle magnetic field and an axial magnetic field are investigated within the framework of fluid-Maxwell equations. The growth rate of free electron laser instability is obtained, in which the nonlinear volume and surface current density are simultaneously considered. The numerical calculations indicate that the volume coupling is dominant. There is a particular value of the beam thickness and the separation between the conducting wall and the beam for which the growth rate becomes maximum.
The effects of the beam thickness and the conducting wall in a free electron laser with a linearly polarized wiggle magnetic field and an axial magnetic field are investigated within the framework of fluid-Maxwell equations. The growth rate of free electron laser instability is obtained, in which the nonlinear volume and surface current density are simultaneously considered. The numerical calculations indicate that the volume coupling is dominant. There is a particular value of the beam thickness and the separation between the conducting wall and the beam for which the growth rate becomes maximum.
1988, 10(1): 65-71.
Abstract:
A formula of phase spectrum density for transistorized amplifier is given. In order to decrease phase noise, optimal design for parameters of amplifier by using Orthogonal Array Table (OAT) is completed. The experimental result shows that the frequency stability (Allen variance) is better than (3-5) 10-13s-1.
A formula of phase spectrum density for transistorized amplifier is given. In order to decrease phase noise, optimal design for parameters of amplifier by using Orthogonal Array Table (OAT) is completed. The experimental result shows that the frequency stability (Allen variance) is better than (3-5) 10-13s-1.
1988, 10(1): 72-79.
Abstract:
In the study of the problems related to the wave propagation in random media, the solutions of the moment equations are often needed. The m-nth moment equation with different wave numbers is a differential equation. In the present paper, the author converts the parabolic differental equation to an integral equation by using the Green s functions. The solution of the moment equation is got by using the iteration method. The solution of the moment equation is also got by using the method of successive scattering. It is shown that the solution by two different mehtods are identical. The physical implication of the successive solution of the m-nth moment equation is explained. Some of the applications of the solutions of the mement equations are discussed briefly.
In the study of the problems related to the wave propagation in random media, the solutions of the moment equations are often needed. The m-nth moment equation with different wave numbers is a differential equation. In the present paper, the author converts the parabolic differental equation to an integral equation by using the Green s functions. The solution of the moment equation is got by using the iteration method. The solution of the moment equation is also got by using the method of successive scattering. It is shown that the solution by two different mehtods are identical. The physical implication of the successive solution of the m-nth moment equation is explained. Some of the applications of the solutions of the mement equations are discussed briefly.
1988, 10(1): 80-84.
Abstract:
A K band wideband coaxial-to-waveguide transducer is described, ts VSWR. is less than 1.1, and its insertion loss is less than 0.1 dB in the frequency range of 12.4 to 18 GHz, The measured results are in good agreement with the calculated ones.
A K band wideband coaxial-to-waveguide transducer is described, ts VSWR. is less than 1.1, and its insertion loss is less than 0.1 dB in the frequency range of 12.4 to 18 GHz, The measured results are in good agreement with the calculated ones.
1988, 10(1): 85-88.
Abstract:
This paper presents the computation results of the minimum peak sidelobe filter (LP filter) for the 15bit m-sequence phase coded waveform with feedback connection [4, 3, 0] and initial condition 1001. The design of the filter resorts to linear programming method. The peak sidelobe level of LP filter of length 15 is reduced to －21.47 dB, and is 7.49 dB lower than that of matched filter. The LP filter can suppress the peak sidelobe even more as increasing its length. The minimum peak sidelobe filter for 15 bit m-sequence phase coded waveform (initial condition 1001) has been implemented with surface acoustic wave (SAW) device. experiments show that the peak sidelobe level of the manufactured filter is －19dB and thus differs from the theoretical value (－21.47 dB) by 2.47 dB.
This paper presents the computation results of the minimum peak sidelobe filter (LP filter) for the 15bit m-sequence phase coded waveform with feedback connection [4, 3, 0] and initial condition 1001. The design of the filter resorts to linear programming method. The peak sidelobe level of LP filter of length 15 is reduced to －21.47 dB, and is 7.49 dB lower than that of matched filter. The LP filter can suppress the peak sidelobe even more as increasing its length. The minimum peak sidelobe filter for 15 bit m-sequence phase coded waveform (initial condition 1001) has been implemented with surface acoustic wave (SAW) device. experiments show that the peak sidelobe level of the manufactured filter is －19dB and thus differs from the theoretical value (－21.47 dB) by 2.47 dB.
1988, 10(1): 89-91.
Abstract:
In this paper, a new type millimeter-wave Gunn oscillator is proposed. The advantages of NRD waveguide and resonant-cap oscillator are employed in the design of the new oscillator. The experimental results show that this kind of oscillator has a good future as a millimeterwave source.
In this paper, a new type millimeter-wave Gunn oscillator is proposed. The advantages of NRD waveguide and resonant-cap oscillator are employed in the design of the new oscillator. The experimental results show that this kind of oscillator has a good future as a millimeterwave source.
1988, 10(1): 92-96.
Abstract:
ABSTRACT In this paper, the formula given by S. Roberts and A. Von Hippel (1946) has been expanded. We make a program for calculating the phase constant of tested material which is put into the waveguide and for obtaining the multi-value solutions. The method for determining r and tan of a rested material does not need special equipments, but it can meet the accuracy requirement for resting ordinary materials.
ABSTRACT In this paper, the formula given by S. Roberts and A. Von Hippel (1946) has been expanded. We make a program for calculating the phase constant of tested material which is put into the waveguide and for obtaining the multi-value solutions. The method for determining r and tan of a rested material does not need special equipments, but it can meet the accuracy requirement for resting ordinary materials.
