Study On High Power Microwave Transmission Line And Mode Conversion

Gyro-devices are new important type of millimeter wave device with the characteristics of high peak power, high average power, high gain, high efficiency and suitability bandwidth and so on. It's very suit for the power source of millimeter wave high capability radar, phase array radar, millimeter wave communication, electronic counter and other systems. Microwave transmission and mode transformers is important part of gyrotron. The energy of gyrotron can be transmission and radiate with requisite methods. Under this background, supported by the "95 Plan" pre-study item and "15 Plan" pre-study item "863 Plan", the microwave transmission and mode converter of high power microwave device and gyrotron are studied with complete theory in depth and numerical simulation. The mode converter with design and machining apply in the experiment of institute of northwest nucleus technology successfully. The work and contribute of this paper is the follow:1. Mode coupling with the bent of axis in a circular waveguide and gradual radius changes of the waveguide in overmoded waveguide is studied. On the base of coupling wave theory, outspread theory of perpendicular function is applied to unwrap the waveguide inner field with the series form of electric wave and magnetism wave. The coupling wave equations and currently expression of coupling coefficient is educed.2. The influence of all kinds of distortions of waveguide in high power microwave system is studied, and the realization condition of energy complete conversion is analysis in detail. Optimal arithmetic and the method to solve coupling wave equation with numerical value is discussed in the different condition. The Mathematic models and the numerical simulation methods have been proved out directly or indirect.The optimal analysis of constant curvature and vary curvature overmoded circular waveguide mode converter geometric configuration with the3. different phase rematch and structure is given. The regulation about the radius of the circular waveguide, curvature of bent circular waveguides, frequency and the bandwidth are obtained. The results are contributed to design corresponding circular waveguide mode converter with the tight, the efficient and the wideband.4. The circular waveguide mode conversion with waveguide radius tapered is discussed in detail. It also carries out the optimized analysis about the geometry structure of TE0n-TE11 , TM0n—TM01 mode converter. Adopting different phase rematch techniques, the optimal geometry parameter can be obtained.5. Novel microwave input method of gyrotron amplifier is explored and discussed. Adopting quasi-optical mode converter, the anode of electronic gun and mode conversion is optimal designed. At the same time, the influence of anode to electron beam is taken into account. Quasi-Optical Mode Converter is mainly adopted vector diffraction theory and Geometry optics theory, and the numerical results of complex reflector are analyzed. Phase and direction of the incidence wave is adjusted by each piece of reflector cell.