FERROELECTRIC CERAMIC FILTERS,IF TRANSFORMERS,AND NETWORKS.

摘要

Research was continued towards the development of ferroelectric ceramic filters,intermediate frequency transformers,and networks. Energy trapping is proposed as an explanation for the behavior of high frequency ATcut quartz resonators. Energy trapping gives a theoretical basis for the high Q sub m observed for quartz resonators mounted on low Q supports and for the low inter-resonator coupling observed for multi-resonator wafers. Measurements in support of the energy trapping theory have been obtained with AT-cut quartz wafers by measuring interresonator coupling and the coupling between resonator and an absorbing edge of the wafer. Some improvement has been obtained in piezoelectric ceramic thickness resonators by using hot-pressing fabrication techniques. Results are discussed for three ceramic fabrication techniques.