Dielectric substrate with selectively controlled effective permittivity and loss tangent

摘要

A substrate ( 300 ) for an RF device includes a plurality of layers ( 102 ) of dielectric material cofired in a stack. The plurality of layers ( 102 ) is formed from a material having a permittivity. Selected ones of the layers ( 102 ) have a pattern of perforations ( 106 ) formed in at least one perforated area ( 104 ). The perforated areas ( 104 ) are generally aligned with one another in the stack to lower one or more of an effective value of a permittivity and a loss tangent in a least one spatially defined region ( 504 ) of the substrate ( 300 ).