The Design Of 15~20kw High-power Microwave Source

Because application prospect of microwave technology is very extensive, design of microwave power system appears more important. With the extensive and deep application of microwave technology in various fields of scientific research, industry and life and higher technological requirements, stable microwave power with high power inevitably will be paid more attention. Microwave power is the core of microwave plasma devices, so instability of the output power will directly restrict the application and development of microwave plasma technology. Therefore, an important task in microwave plasma technology is to study high-power microwave power with high stable output.At present, this field has larger differences at home and abroad. Foreign countries have already used magnetron CWM-100 L with L-wave 915 MHZ produced by German MUEGGE company to design the microwave power with the highest output power of 100 KW. By contrast, domestic level still rests on under 20 KW output power.Magnetron is a core power electronic device of gaining high-power microwave energy. Its characteristics are similar to high-frequency diode in the space of crossed electric and magnetic field. In practical application, because working conditions of magnetron are extremely strict, if there is perfect control scheme, output power of magnetron will be impacted by subtle cathode voltage or anode current fluctuation, so as to produce output power with larger ripple factor.The experimental result indicates that once magnetron turns into normal working, if threshold voltage of magnetron keeps still, cathode voltage can be regarded as constant approximately. Thus, this paper puts forward a kind of control scheme aiming at anode current adjustment of magnetron on the basis of SCM ATmega16 L to detect, sample and deal with anode current of magnetron and work out control parameters by adjusting algorithm with incremental P(proportion—integral), while providing stable output voltage by magnetron, so as to adjust size of magnetic field current value effectively and ultimately achieve the goal of obtaining stable output of microwave power.The design selects and adopts CK-611 high-power magnetron. The following content elaborates its characteristics and operating principles. Meanwhile, it also conducts deep analysis on current various common microwave power control schemes, summarizes, compares and puts forward the optimum control scheme, and elaborates implementation methods of specific software and hardware for each functional circuit part in the control scheme, and late debugging of each part.This paper completes comparison, analysis, design, ultimate verification and debugging, etc., a series of work in the control scheme, puts forward a new reference scheme for obtaining microwave power with 20 KW high-power stable output. Based on it, by upgrading and improving the system constantly, perfecting protective circuit, repeatedly inspecting circuit layout, ultimately expectant effect can be obtained.