To provide a dielectric filter, a dielectric duplexer and a communication apparatus equipped with them in which attenuation peak are generated on both lower-frequency and higher-frequency sides of a passband without extremely narrowing a pitch of a resonant through hole.
A dielectric block 1 includes resonant through holes 4a-4d that are arranged adjacent to each other. A multipath slot 11 is arranged near the three adjacent through holes 4a, 4b, 4c. The multipath slot 11 forms a conductor to generate a capacitance between an area near the open end of each of the three adjacent through holes and the conductor of the multipath slot. A step 13 is formed that generates capacitance positively between an area near the open end of each of through holes 4c, 4d and an outer conductor. An attenuation peak is generated at the lower-frequency side of the passband with a resonator composed of the three through holes 4a, 4b, 4c, and an attenuation peak is generated at the higher-frequency side of the passband with a resonator composed of the two through holes 4c, 4d.
TADA HITOSHI
KATO HIDEYUKI
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