Secmotron (Sector beam deflection modulation tube) is a new kind of high efficient microwave tube which is developed on the basis of gyrocon. The principle of gyrocon has been analyzed and it manifests that to increase circuit efficiency is necessary for improving properties of a gyrocon. One of the key points is to increase its perveance. An idea about sector beam is proposed to reduce the effect of space charge. Also the concept and construction of transforming a column beam into a thin sector beam are presented. The numercal calculation of some specific structures demonstrates that above idea is realizable.

Theoretical and experimental research have been done for external TWT equalizer by using microstrip circuit. In order to further improve the performance of TWT, a CAD method is employed to optimize the circuit parameters, and then the gain variation can be reduced from 11.2 dB to 2.74 dB at a bandwidth of 2.8-7.0 GHz. A two-stage equalizer has been also tested. After adjusting six parameters in the microstrip circuit by the use of computer, the gain variation could be reduced from 13.6 dB to 2.73 dB at a bandwith of 2.5--7.5 GHz. But the experimental results is about 5 dB. The deviation between them is analyzed qualitatively.

The dispersion characteristics of the shielded planar transmission lines are analyzed by the transverse resonance method combining with variational technique. Two shorting planes are transversely inserted in the propagation direction so as to form a closed resonator. The dominant mode propagation constant of a transmission line is related to the distance be-tween shorting planes through the resonant condition. The characteristics equation for the distance is derived by using the variational formulation for a generalized resonator. The numerical results for the finlines are given. A comparision is made with available data in literatures.

It is developed that a new hyperstable adaptive algorithm which can be used in the multichannel IIR configuration and/or the high-order IIR configuration for joint process estimation.

The problem for the solvability of pseudo-tearing subnetwark is one of essential investigations of network theory. The results presented would be not only a mathematical conditions, but also a topological conditions for subnetwork solvability. It should guide intuitively to the design of accessible nodes.

In anomalous dispersion of monomode optical fiber, an optical soliton is evolved from an optical pulse in the fiber when the nonlinearity is balanced by dispersion. Transmission without distortion, which can greatly improve the capacity and relaying distance of the optical communication system, can be realized by using optical solitons. The mechanism of the generation of optical solitons is expounded. Afew forms of nonlinear transmission equation are obtained by using a simple and clear method. The general complete expression of elementary soliton solution of the nonlinear transmission equation without losses is given, and the design of the soliton transmission system is discussed.

The coupling effect between axial slots on the surface of conducting cylinder covered with a dielectric layer is studied. The convergence of infinite integral in spectral expansion of coupling coefficients is discussed. The calculation formula of coupling coefficients it obtained by introducing the subsidiary function Ge. Some calculated results are given.

The dispersion equation is derived by using the equivalent circuit method for periodical waveguides with double conical slow-varying cross-sections. Some dispersion curves with different parameters of the construction are calculated. Thus, the theoretic basis is provided for selecting optimum dimensions to realize the wide-band gyrotron designs. Finally, theoretic predication is demonstrated by experimental results.

A detailed analysis for the backward wave free electron laser (FEL) in small signal regime is conducted, following the single partical approach. By the use of a modified factor F_m, the formulas resulted are similar to those of normal FELs. To compare with normal FELs, these formulas show that the backward wave FELs have two main features: the high energy conversion! effeciency and the loose e-beam quality requirement. So it is suitable to be one stage of the two-stage FEL.

A real-time recursive algorithm of Householder transform and the proof of its convergency are given, and this algorithm is used for AR adaptive spectral estimation. The simulating computation shows that this algorithm has the features of correct computation results, real-time determination of order and excellent fast tracking.

The physical and electrical properties of BF⁺₂ implanted polysilicon film subjected to rapid thermal annealing (RTA) are presented. It is found that the out diffusion of F and its segregation at polysilicon/silicon oxide interface during RTA are the major causes of F anomalous migration. Fluorine bubbles were observed in BF⁺₂ implanted samples at doses of 1×10¹⁵ and 5×10¹⁵cm^-2 after RTA.

Energy gap and minority-carrier recombination lifetime are important physical parameters in the emitter of silicon transistor. Using temperature characteristics obtained from the reverse diffusion current of p-n junction and by means of linear extrapolation, a new method for determination of the energy gap at 0K is presented. Based on the carrier Fermi-Dirac statistic distribution, a method for determination of minority-carrier recombination lifetime in highly doped emitter is presented. This test method is simple and can be used in practice.

The preparation, principle and measured results of complex ion sensitive field effect transistor (ISFET) with Ag-AgCl reference electrode are described. Through theoretical analysis and experiments, the feasibility of Ag-AgCl reference electrode which does not contact with solution and the way of overcoming its unstability are put forward. It is explained that why the effect appearing in the ISFET does not conform to Nernst effect, when Na⁺, Ca⁺⁺ cations etc. are measured with Ag-AgCl reference electrode.

A numerical analysis is presented in terms of finite element of hybrid-mode propagation characteristics in microstrip transmission lines, which include characteristics impedance, velocity ratio, dispersion characteristic and the effect of strip thickness. The results of calculation are compared with previous approximate calculations. It is shown that the finite-element method is an efficient numerical analysis for microstrip transmission lines.

EM transmission and scattering characteristics of radome may Conveniently be analyzed by complex ray paraxial approximation and collective ray methods. 2-D cylindrical radomes are analyzed and calculated, including radome transmission coefficient, radar angular track property and radar cross-section of radomes, as well as the effect of ray parameters and antenna-radome parameters on computation accuracy. It is shown that this method can be used to simplify optimization designs for many kinds of radomes.

The effect of a longitudinal electric field on whistlers is studied based on kinetic theory. A local Maxwellian distribution is taken as steady distribution function of electrons which departs from equilibrium due to the applied electric field. The dielectric tensor is derived by integrating along orbits of the particles in the unperturbed field. Dispersion relation and growth rate are analyzed from Hermitian and anti-Hermtian part of this tensor respectively. It is found that the waves are growing when the angle between wave vector and electric field is in the range of θ_c, otherwise the whistler waves are damping. The growth rate increases with the wave frequency and decreases with the angle between wave vector and applied field. In case ω_e>>Ω_e, the maximum of growth rate, which is at θ=0, is proportional to the plasma density and anti-proportional to the magnetic field intensity. Some computed results for parameters at top of F layer are given.