The Study Of Dual-frequency And Multi-frequency Relativistic Backward Wave Oscillator With New Pattern Resonant Reflector

Since the1970s, the development of high power microwave（HPM）technology, notonly created a new application field, but also provided new ways for the application ofexisting microwave research. In the high power microwave system, the microwavesource which converts high power electric pulse to electromagnetic wave, is the corepart of the whole system. Foreign researchers have found that beat microwave radiationwhich produced from synthesis of close dual-frequency or multi-frequency HPM canreduce the threshold of the destruction when electronic system is attacked. Somicrowave device which has dual-frequency (multi-frequency) HPM output caused theattention of researchers both at home and abroad. Because of its lower cost, bettersynchronization, easier implementation in actual applications, the device which cangenerates dual-frequency (multi-frequency) microwave at the same time has moreadvantages. But now the dual-frequency HPM source also faces many technicalproblems, including efficiency and the stability of the output. Relativistic backwardwave oscillator (RBWO) is the main research object in this thesis. In order to improvethe stability and efficiency of the dual-frequency output, two kinds of new patternresonant reflectors with dissymmetric structures were designed and used in the designof multi-frequency coaxial relativistic backward wave oscillator (CRBWO). With thehelp of2.5-D particle-in-cell (PIC) simulation code CHIPIC, stable dual-frequency wasobtained in CRBWO. And multiple-frequency (three and four-frequency) output wasobtained in CRBWO with the resonant reflector which has better stability in HPMoutput. Main content of this article are as follows:1. The history and development of high power microwave technology wereintroduced. The researches of single frequency and dual-frequency HPM source weresummarized. The purpose and meaning of the research in this thesis were expounded.2. Analyses on backward wave oscillator (BWO) and RBWO were made. And themethods of improving efficiency were discussed.3. Methods of generating dual-frequency radiation in RBWO were brieflyintroduced. 4. Two kinds of new pattern resonant reflectors with dissymmetric structures arepresented and used in the design of dual-frequency CRBWO. With the help of2.5-Dparticle-in-cell (PIC) simulation code CHIPIC, stable dual-frequency was obtained inCRBWO with the new pattern resonant reflectors.5. With electron beams of480kV and7.5kA, guided by a magnetic field of2.7Tesla, stable multiple-frequency (three and four-frequency) output was obtained inCRBWO with the second new pattern resonant reflector which has better stability inHPM output. The efficiencies are15.3%and13.9%which are higher than othertraditional device.6. The full text was summarized, and the next step of work plan was proposed.