| 摘要 |
PURPOSE:To obtain a microwave filter with excellent isolation characteristic by mounting a shield plate to an electrode for mounting the shield plate formed to an open end of a dielectric block so as to eliminate the coupling of coaxial resonators due to an electromagnetic wave leaked from the open end of the dielectric block. CONSTITUTION:A face opposing to a face formed with a short-circuit conductive film 19 of the dielectric block 15 becomes an open end 22 of coaxial resonators 21-1, 21-2.... Shield plate mounting electrodes 23-1, 23-2... connected to the conductive film 18 in the broadwise direction of the dielectric block 15 are formed between the coaxial resonators 21-1 and 21-2 of the open end 22, between the coaxial resonators 21-2 and 21-3, between ... and one end of the shield plates 24-1, 24-2... is soldered to the shield plate mounting electrodes 23-1, 23-2.... The other end of the shield plates 24-1, 24-2... is soldered to a case 14. The coupling between coaxial resonators part by one resonator or over due to the electromagnetic wave leaked from the open end 22 of the dielectric block 15 and the deterioration in the band pass characteristic of the microwave filter is prevented. |
