The Research In Theory And Application Of Frequency Selectiviy Of The Non-Magnetized Cold Plasma

The development of modern communication has driven a higher demanding on microwave devices. Novel microwave devices with plasma technologies become new research hotspots due to the fast tunablity of the plasma.In this paper, based on the basic electromagnetic characteristics of plasma, the frequency selectivity of the non-magnetized plasma and its application in inhibiting parasitic pass-band of microwave filters are studied carefully. Concretely, the first work is to analyze and approve the high-pass property of the plasma, metal-like characteristic to the frequency which is lower than plasma frequency, and the band-pass property of layered structure called 'sandwich' filled with plasma through the research of reflection and transmission coefficients. And then, based on the frequency selectivity of the non-magnetized plasma, a new method for inhibiting parasitic pass-band of microwave waveguide filters is put forward. Using this method, this paper designs a case of microwave waveguide filter in which the plasma layer is putted in one end of input and output coupling structure of the filter in order to inhibit parasitic pass-band of frequency tripling. And its simulation results show that this method can inhibit parasitic pass-band to lower than -20dB and this result can be further optimized. In addition, the filter's tunablity, the manufacture scheme, plasma generating and measurement experimental methods of plasma microwave devices are studied. Finally, a distributed simulation platform for designing plasma microwave devices is developed in order to assist some stand-alone simulators in processing batch tasks.