Dual-band multilayer ceramic microwave bandpass filter for application in wireless communication

A dielectric multilayer dual-band filter is realized by using stepped-impedance resonator (SIR). The input / output ports of the filter are formed with transmission lines directly tapped to the resonators. The admittance matrix for the equivalent circuit of the filter has been derived and transformed to the scattering matrix to initially determine the required spec. Losses and other EM effects are taken into account to further modify the actual dimension of the designed filter. The designed structures are simulated using an IE3D simulator. The response of the fabricated filter is measured using an HP8757D network analyzer. Sample results of the filter performances demonstrate responses, in good agreement with the computer simulations.