DIELECTRIC FILTER AND ANTENNA COUPLER EMPLOYING THE FILTER, AND COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To solve a problem of a conventional small-sized dielectric filter used for high frequency radio devices or the like that a current distribution of a resonator is concentrated onto an end of a resonator electrode to increase a conductor loss resulting in deteriorating the filter characteristic because conventional layered dielectric boards are all made of the same material and the dielectric constant of them is identical to each other. SOLUTION: An upper side ground electrode dielectric board 11b, an inter- stage coupling capacitance dielectric board 11c, a resonator dielectric board 11d, and an input output coupling capacitance dielectric board 11e are configured with a composite dielectric board comprising, that is, a 1st dielectric material 16 with a high specific dielectric constant and a 2nd dielectric material 17 with a low specific dielectric constant.