Design Of The Band-stop Filter With Stepped Impedance Resonator

With the development of wireless communication technology, the requirement of the microwave filters has been increasing. Its performances also have been required. In modern communication systems, bandstop filter as the front components of the RF system plays very important role. Currently, Stepped Impedance Resonator (SIR) as a novel class of resonator structure has been widely used in the design of filters because its harmonic frequencies can be adjusted by tuning the impedance ratio. In this thesis, we have analyzed and explored the bandstop filters based on SIR technology.The content of this thesis is as follows:First, a band-stop filter with central frequency of 3.0GHz is designed and implemented based on the open-end annular SIR. This filter exhibits compact szie compared with the conventional bandstop filter based on half-wavelength resonator. Second, using the cross coupling technique, a bandstop filter with central frequency of 4.1 GHz utilizing the cul-de-sac type SIR is proposed. Final, making use of the cross coupled bandstop filters mentioned previously, a dual-band bandstop filter is presented. The lower stop-band arrangs from 2970MHz to 3030MHz and the higher stop band varys from 4070MHz to 4130MHz?Thereafter, various bandstop samples are fabricated and measured. The measurement agree well with the simulation.