Abstract: Design of ladder-type RF filters based on the film bulk acoustic resonators(FBARs) is presented based upon Mason equivalent circuit model.Previous work did not take acoustic attenuation in the medium into account;therefore the effect of media loss on the obtained filter frequency response was neglected.Considering acoustic attenuation of the medium,the RF network method is used in filter modeling.Some key problems in filter design,such as transmission response,bandwidth,insertion loss,out-band rejection and passband ripples are investigated and analyzed.