| 摘要 |
PURPOSE:To provide satisfactory filter characteristics preventing a Q value from being lowered when the load of a coaxial resonator is high by eliminating a ridge line part formed by the two faces of a face, which forms the inter-step coupling window of the resonator, and a face adjacent to this face in counter to a substrate. CONSTITUTION:A dielectric block 1 composed of dielectric ceramic is compacted and sintered by a die almost in a prismatic shape eliminating a ridge line part 1c formed by a first face 1a and a second face 1b and afterwards, an outer conductor 3 and an inner conductor 4 are formed by covering the outer and inner peripheral faces with a conductive member while remaining an open end face 2. Further, a window 5 for inter-step coupling is formed by removing the outer conductor on the second face 1b and removing one part of the outer conductor on the first face 1a adjacent to the second face 1b so that a coaxial resonator 6 can be completed. Thus, even when the inter-step coupling window 5 is formed on the second face 1b by a dicing saw 7, the leakage of an electromagnetic substance is suppressed by the outer conductor 3 remained between the first face 1a and the second face 1b. |
