Patent ID: 7400221

Claim:
A semi-coaxial cavity resonator comprising: an outer conductor having a cavity therein; and a columnar inner conductor fixed at a bottom surface of the cavity, but not fixed at an upper surface facing the bottom surface of the cavity, wherein the inner conductor has a hole therein with an internal thread being formed at the hole, and is fixed at the bottom surface of the outer conductor with a screw, a surface roughness (Ra) of each of a contact surface of the inner conductor and that of the outer conductor is equal to or less than 1.6 μm; wherein a contact pressure of (5T/d)/S≧60 MPa is established, where S (m 2 ) is an area of the contact surface, T (N·m) is a tightening torque of the screw, and d (m) is a diameter of the screw, the hole of the inner conductor has an inner cavity that is not engaged with the screw, at a region directly above the bottom surface of the outer conductor, and a height of the inner cavity is equal to or more than a radius of the screw, and a length of a portion of the screw being engaged with the internal thread is equal to or less than twice the diameter of the screw.