JPS6453604A - Dielectric filter - Google Patents

Abstract

PURPOSE:To effectively suppress the spurious of an odd number higher order mode by changing the size of the additional electrode of respective resonators beforehand when plural dielectric resonators are combined and a filter is formed. CONSTITUTION:On the inner circumferential surface, outer circumferential surface and lower surface of cylindrical dielectric elements 31-33, electrodes 34-36 and 34'-36' are formed by metallization, plating and so forth. On the upper surface, additional electrodes 37-39, which are connected with the electrode of the inner circumferential surface and individually different in the size, are formed by the metallization, plating and so forth and lambda/4 type dielectric conductor resonators 40-42 are formed. On the inner circumferential surface of respective dielectric resonators, conducting material shafts 43-45 are inserted, and further, bonded to electrodes 48-50 formed by the metallization, plating and so forth with solderings 52-54 and unified on the main surface of another dielectric substrate 46. Electrodes 47 and 51 of both edges of the substrate 46 are made into the input output terminal. Thus, the spurious of odd numbered higher order modes can be effectively suppressed with a simple consturction.