Patent ID: 6420947
Filing Date: 2002-07-16
Classification: H01P

Abstract:
A microwave filter comprising at least one cavity defined by a cylindrical side wall and two planar end walls having two opposite major surfaces whose perimeters are respectively attached by attachment means to an outwardly extending flange means at each end of said side wall, said side wall being made from a metallic material having a low coefficient of thermal expansion and said two end walls being made from a metallic material having a relatively high coefficient of thermal expansion, wherein a first continuous annular groove of a predetermined depth and a predetermined minimum width is provided in one major surface of each end wall proximate its perimeter, and a second continuous annular groove of predetermined depth and a predetermined minimum width is provided in the other major surface of each end wall proximate said perimeter, the diameter of said first annular groove being greater than the diameter of said second annular groove whereby a solid intermediate zone of predetermined width lies between the first and second annular grooves, and wherein a plurality of open ended slots of predetermined minimum width are provided in each said planar end wall at its perimeter, said slots extending from proximate said first annular groove to the outer boundary of said planar end wall.