Patent ID: 8299875

Claim:
A cavity filter, comprising: a bottom portion; one or more sidewalls extending from edges of the bottom portion so as to define a cavity therebetween and an open top; a plurality of resonators each secured on the bottom portion of the cavity and defining a resonating body in communication with the cavity; a lid to cover the opening of the cavity and comprising a plurality of bases each extending from the lid toward one of the plurality of the resonators; a plurality of threaded holes each penetrating the lid and one of the plurality of bases and comprising a stopper portion extending from an inner surface of the threaded hole inward to form a step defining a through hole in communication with the threaded hole; a plurality of sticky elements each located on the step of one of the stopper portions; and a plurality of tuning posts each comprising a threaded portion and a tuning rod extending from the threaded portion; wherein when a resonating frequency of the cavity filter is adjusted, the threaded portion of each tuning post is received in one of the plurality of threaded holes, and the tuning rod of each tuning post traverses through the through hole of the step of the threaded hole, metal shavings produced when the resonating frequency of the cavity filter is adjusted are retained in the steps of the stopper portions.