Design of narrow-band transversely coupled and balanced bridge resonator filters using equivalent circuit and P-matrix models

This paper reports on two methods of designing narrow-band resonator filters: the modified equivalent circuit model for transversely coupled resonator filters and modified P-matrix model for balanced bridge resonator filters. To raise the accuracy of simulation on the basis of both the models, we use the experimental parameters obtained for the two-resonator structure of the filter being designed or for individual resonators of the filter. The experimental data and theoretical predictions agree well for the yx1/33.3° quartz filters with central frequency 86.8 MHz and bandwidth 56 kHz