| 摘要 |
PURPOSE:To make the coefficients of linear expansion of a cylindrical dielectric body and a case arranging said dielectric body coincide with each other and to improve the temperature characteristics of resonance frequency by forming the cylindrical dielectric body constituting a dielectric resonator and at least a part of the case by the same dielectric material. CONSTITUTION:A resonator body part 13 is equipped with a dielectric case side part 14 and a dielectric cylindrical part 15 arranged concentrically in a cave 17 formed by the side part 14 and unitedly coupled by four cupling parts 16. A conductive film 18 is formed on the whole external surface of the side part 14. Conductive films 19, 20 are also formed on the lower surface of an upper cover 11 and the upper surface of a lower cover, and when these covers are set up, shielding and a real current path corresponding to an ordinary metallic case are formed by the films 18-20. Since the cylindrical dielectric body and the case are constituted by the same material, the coefficients of linear expansion of both parts coincide with each other and a minute gap between the end surface of the dielectric body and the case is removed or uniformed constantly. Thus, the temperature characteristics of resonance frequency are extremely improved. |
