X-band Overmoded Waveguide High-power Microwave Pulse Compression Technique

This paper is focused on the research of excessive modes cylindrical cavity pulse compression technology of X-band High Power Microwave.By developing this research, it is possible to synthesize microwave power, supply proper HPM power of narrow pulse for the research of HPM effect and HPM atmosphere broke, and improve radar system in existence.This paper stresses on the excessive modes cylindrical cavity pulse compression technology. Selecting the method of SES (switch energy storage) and using a spontaneous breakdown gas switch, the low and high input power experiments of both rectangular cavity and excessive modes cylindrical cavity pulse compression systems are done. Comparing with rectangular cavity system, the excessive cylindrical modes cavity pulse compressed system is superior.In theory, by use of such theories as wasting transmission line, microwave equivalent circuits, network matrix of electromagnetism and so on, the process of energy storage and energy dumping of pulse compressed system of excessive modes cylindrical and rectangular cavity is analyzed. Ultimately, the power gain and energy storage efficiency formulas are found out. After analyzing gas switch's effects on the system of pulse compression and adopting correctional factors, the primary theoretic formulas are mended and the primary theories are perfected.In low input power experiments, the input storage factor of the excessive cylindrical modes cavity pulse compressed system is about 10406, much bigger than rectangular cavity's, which is about 4704. Therefore, it is proved by theory that the excessive cylindrical modes cavity pulse compressed system is superior on the aspect of power gain.As for high input power experiments of the excessive cylindrical modes cavity pulse compressed system, on the condition of normal temperature, normal pressure and X band's microwave frequency, when the input pulse power is 50.2kW and the input pulse width is 1μs, the out pulse maximal power is 479kW and the out pulse width is about 26ns.thus the maximal power gain is 9.4 and the compressing efficiency is 24.4%.In the contrast, for rectangular cavity system, when the input pulse power is 54.8kW and the input pulse width is 1μs, the out pulse maximal power is 234kW and the out pulse width is about 18ns.thus the maximal power gain is 4.3 and thecompressing efficiency is 5.6%. Therefore, it is proved experiments that the excessive cylindrical modes cavity pulse compressed system is superior to the rectangular cavity pulse compressed system on the aspect of such as power gain, compressing efficiency and so on.