Coaxial resonator

摘要

A 1/4 wave length coaxial resonator comprises an outer cylindrical portion, an inner cylindrical portion positioned coaxially in the outer cylindrical portion, with the outer and inner cylindrical portions connected at one end by a radial connecting portion, and a dielectric unit disposed therebetween. The outer cylindrical portion and the inner cylindrical portion and the radial connecting portion are formed with a unitary member of a metallic extruded material formed by means of an impact extruding process so that the inner cylindrical portion is positioned coaxially in the outer cylindrical portion. As a result, a space is formed between the outer cylindrical portion and the inner cylindrical portion to allow for insertion of a hollow cylindrical dielectric unit. One end of the above described metallic extruded member of a unitary material is formed as an opened end allowing for insertion of the dielectric unit, while the other end of the metallic extruded member is formed as a radial connecting portion for electrically short-circuiting the outer cylindrical portion and the inner cylindrical portion. The dielectric unit is formed with an outer conductor layer on the outer wall surface and an inner conductor layer on the inner wall surface. The dielectric unit is inserted only in the region close to the opened end or in the whole portion of the space between the outer cylindrical portion and the inner cylindrical portion.