| 摘要 |
PURPOSE:To maintain a stable characteristic even if a peripheral temperature changes by providing a metallic plate constituting a resonant cavity in cooperation with a metallic case. CONSTITUTION:When the metallic case 12 and the metallic plate 14 are respectively provided on the upper surface and the lower surface of a circuit board 16, through holes 20 and 30, and a machine screw hole 32 are positioned and a machine screw 18 is inserted into the machine screw hole 32 through the through holes 20 and 30, the metallic case 12, the circuit board 16 and the metallic plate 14 are reciprocally and integrally fixed. Thus, space regulated by the metallic case 12 and the metallic plate 14 comes to the resonant cavity for a dielectric resonator 24. Since the metallic plate 14 is arranged on the lower surface of the circuit board 16 and is integrally fixed with the metallic case 12, and a ground pattern 28 is closely brought into contact with the metallic plate 14 in fitting structure as illustrated, the deformation of the circuit board due to a temperature change is restricted, and the capacity of the resonant cavity is prevented from changing. |
