PURPOSE: To make large the attenuated amounts of a high-pass band, and to reduce a pass loss by connecting an resonance circuit in which a coaxial type dielectric resonator is serially connected with a capacitance, with one of input and output terminal sides.
CONSTITUTION: Plural coaxial type dielectric resonators 3 are connected in parallel through an inter step capacitance 4, and an input and output capacitance 2 is provided between input and output terminals 1 for connecting the initial and final steps of the coaxial dielectric resonators 3 with an outside circuit. Then, an attenuated amount suppressing resonator circuit in which the other coaxial dielectric resonator 5 is serially connected with a capacitance 6, is connected with the input and output terminal 1. And also, the resonance frequency of the resonance circuit is set to be odd number times as high as the basic pass frequency of the circuit in which the coaxial dielectric resonators 3 are connected in parallel through the inter step capacitance 4. Therefore, the large attenuated amounts can be obtained at the higher pass band than the basic pass band of the filter, that is, odd times as high as the basic pass band.
EGUCHI KAZUHIRO
YONEDA TAKEHIKO
TAGI HIROMITSU
