Millimeter Wave Filter for Wireless Communications Systems

Abstract

A millimeter wave transmission line filter having a plurality of filter pole determining coupled cavities fabricated with a multiple lithographic layer micro-machining process. The filter cavities are oriented perpendicular to an underlying substrate element in order to achieve micromachining, fabrication and accuracy advantages. Multiple filters can be used in a frequency multiplex arrangement as in a duplexer. Radio frequencies in the 15 to 300 gigahertz range are contemplated.

1 . A millimeter wave transmission line filter comprising:
 a plurality of adjacently located, open-ended, radially intersecting, millimeter wave sized cavities disposed in a body of electrically conductive material; and   a thinly disposed unitary array of cavity-tuning-capacitive closure elements compatible with the open-ended intersecting cavities at the open end thereof, wherein the body of cavities and the unitary array of cavity-tuning capacitive closure elements include mutually engageable marriage elements.   
     
     
         2 . The millimeter wave transmission line filter of  claim 1 , further comprising:
 a first plurality of the adjacently located, open-ended, radially intersecting, millimeter wave sized cavities and first cavity-tuning-capacitive closure elements disposed into a first electrical wave filter element of first wavelength selection characteristic; and   a second plurality of the adjacently located, open-ended, radially intersecting, millimeter wave sized coaxial cavities and second coaxial cavity-tuning-capacitive closure elements disposed into a second electrical wave filter element of second differing wavelength selection characteristic; and wherein   the first and second pluralities comprise a duplex electrical wave filter.