Un-symmetric two half-wavelength resonators bandpass filter design and its equivalent circuit model

An equivalent circuit model for an un-symmetric two lambda/2 resonators bandpass filter is proposed in this paper. The parameters of the equivalent circuit parameters are determined by combination of the direct parameter-extraction technique and optimization method. Both the extrinsic and intrinsic parameters in the equivalent circuit are determined by using direct extraction technique as the initial values for optimization. The calculated frequency response of the equivalent circuit model for the structure agrees well with the simulated results both in magnitude and phase.