Research On RF MEMS Filters Based On EBG Technology

The EBG(Electromagnetie Bandgap) structure is a kind of structures,which has some special characteristics, such as periodic bandstop, slow wave and high effective characteristic impedance. It can suppress the propagation of electromagnetic waves in a specified frequency band and in some directions, which has been widely used in the design of microwave circuits.Microelectronic mechanical systems (MEMS)is a new disciplines that developing interdisciplinary based on the microelectronic technology. It depends on microelectronic technology and machining technology, which ranges from microelectronics,mechanics, automatic control, materials science and other disciplines of engineering.According to basic couldn't adjusted microwave circuit,the author has done much research on model analysis method and transmission characteristic of CPW. Dumbbell shaped CPW with its equivalent circuit is analyzed in detail and traditional design methods and study hotspots of filters in recent years are discussed.Then, the effect of changing several parameters of dumbbell shaped CPW is analyzed and discussed particularly. Based on the study and analysis of dumbbell shaped CPW, a new type of tunable CPW is proposed, and its performance is discussed with electromagnetic simulation.After that, a broadband band-stop filter is designed based on the improved compact CPW, the filter shows sharp selectivity and deep attenuation levels on the stop band, the big range change of center frequency has been realized while size was not altered. At last, a tunable filter is released by RF-MEMS technology.