Patent ID: 6040739
Filing Date: 2000-03-21
Classification: H01P

Abstract:
A millimeter microwave amplifier module assembly, comprising:a metal base plate, said base plate having an upper surface and a lower surface, and being of a predetermined thickness and relatively rigid in characteristic;said metal base plate including first and second rectangular waveguide passages, said passages being spaced apart and extending between and through said upper and lower surfaces to permit propagation of rectangular mode microwave energy;said first and second rectangular waveguide passages comprising a rectangular cross section geometry;first and second tooling pins, said first and second tooling pins being mounted to said base plate on opposite sides of said first waveguide passage and extending from and oriented perpendicular to said upper surface;said first tooling pin being of a first length and said second tooling pin being of a second length, and said second length being greater than said first length;third and fourth tooling pins, said third and fourth tooling pins being mounted to said base plate on opposite sides of said second waveguide passage and extending from and oriented perpendicular to said upper surface;said third tooling pin being of said first length and said fourth tooling pin being of said second length;a substrate of dielectric material bonded to said upper surface of said base plate, said substrate including a first rectangular dielectric region covering an end of said first rectangular waveguide passage and a second rectangular dielectric region covering an end of said second rectangular waveguide passage, said substrate being of a predetermined thickness and including guide holes for receiving there through said first, second, third and fourth tooling pins;a first metal ring frame attached to said upper surface of said substrate; said first metal ring frame extending about the periphery of said first rectangular dielectric region and containing a passage there through;a first plurality of electrical vias, said first plurality of electrical vias extending from said first metal ring frame through said substrate for electrical contact with said metal base plate;a second metal ring frame attached to said upper surface of said substrate; said second metal ring frame extending about the periphery of said second rectangular dielectric region and containing a passage there through;a second plurality of electrical vias, said second plurality of electrical vias extending from said second metal ring frame through said substrate for electrical contact with said metal base plate;a first microstrip transmission line and a second microstrip transmission line attached an upper surface of said substrate;said first microstrip transmission line extending through said passage in said first metal ring frame to said first rectangular dielectric region, said first microstrip transmission line being electrically insulated from said first metal ring frame, and said second microstrip transmission line extending through said passage in said second metal ring frame to said second rectangular dielectric region, said second microstrip transmission line being electrically insulated from said second metal ring frame;a first coupling probe attached to said upper surface of said substrate; said first coupling probe extending into said first rectangular dielectric region and having an end connected to said first microstrip transmission line for coupling microwave energy to said first microstrip transmission line;a second coupling probe attached to said upper surface of said substrate; said second coupling probe extending into said second rectangular dielectric region and having an end connected to said second microstrip transmission line for coupling microwave energy to said second microstrip transmission line;a first metal backshort member for said first rectangular waveguide passage;said first metal backshort member including an exterior surface containing a rectanguloid shaped portion and a flange laterally extending therefrom and extending about a bottom end of said rectanguloid shaped portion, said flange thereof having a predetermined flange thickness;said flange thereof including first and second guide holes for respectively receiving there through said first and second tooling pins;said first metal backshort member further including an interior surface defining a metal walled rectangular microwave cavity having a rectangular cross-section geometry congruent with said cross-section geometry of said first rectangular waveguide passage and having an open front wall;said first metal backshort member further including a bottom end defining a frame to said open front wall of said microwave cavity;said first metal backshort member further defining a metal walled lateral passage leading from the exterior of said first metal backshort member through said frame and a side wall of said microwave cavity into said microwave cavity, said metal walled lateral passage being oriented perpendicular to said side wall of said microwave cavity and being open on a bottom side;said first metal backshort member being positioned on said dielectric substrate with said bottom end of said first metal backshort member abutting said first ring frame and said open front wall of said microwave cavity therein oriented facing and in alignment with said first rectangular dielectric region; and with said metal walled lateral passage thereof overlying said passage through said first ring frame;a first resilient compressible gasket; said first resilient compressible gasket being of a predetermined height and width and defining a U-shaped portion to fit on said flange of said first metal backshort member and collar said rectanguloid portion thereof;a second metal backshort member for said second rectangular waveguide passage;said second metal backshort member including an exterior surface containing a rectanguloid shaped portion and a flange laterally extending therefrom and extending about a bottom end of said rectanguloid shaped portion thereof, said flange thereof being of said predetermined flange thickness;said flange thereof including third and fourth guide holes for respectively receiving there through said third and fourth tooling pins;said second metal backshort member further including an interior surface defining a metal walled rectangular microwave cavity having a rectangular cross-section geometry congruent with said cross-section geometry of said second rectangular waveguide passage and having an open front wall;said second metal backshort member further including a bottom end defining a frame to said open front wall of said microwave cavity thereof;said second metal backshort member further defining a metal walled lateral passage leading from the exterior of said second metal backshort member through said frame and a side wall of said microwave cavity thereof into said microwave cavity, said metal walled lateral passage being oriented perpendicular to said side wall of said microwave cavity and being open on a bottom side;said first metal backshort member being positioned on said dielectric substrate with said bottom end of said backshort abutting said second ring frame and said open front wall of said microwave cavity therein oriented facing and in alignment with said second rectangular dielectric region; and with said metal walled lateral passage thereof overlying said passage through said second ring frame;a second resilient compressible gasket; said second resilient compressible gasket being of said predetermined height and width and defining a U-shaped portion to fit on said flange of said second backshort member and collar said rectanguloid portion thereof;a metal cover plate for attachment to said metal base plate; said metal cover plate including a top side and a bottom side, said cover plate being relatively rigid and having a predetermined thickness;said cover plate including a pair of guide holes for receiving therewithin respective ones of said second and fourth tooling pins;said bottom side of said cover plate including a peripheral edge portion and bounding a first recessed portion, recessed from said bottom end, to fit over said substrate, wherein said peripheral edge portion contacts said metal base plate and said upper surface of said substrate is received within said recessed portion without contact between said cover plate and said first and second microstrip transmission lines when said cover plate is attached to said metal base plate;said bottom side of said cover plate including a second recessed area located within said first recessed area for receiving there within said rectanguloid portion of said exterior surface of said first metal backshort member, said second recessed area being further recessed from said bottom than said first recessed area;said bottom side of said cover plate including a third recessed area located within said first recessed area for receiving there within said rectanguloid portion of said exterior surface of said second metal backshort member, said third recessed area being further recessed from said bottom than said first recessed area;said bottom side of said cover plate including a fourth recessed area located within said first recessed area and contiguous to said second recessed area for receiving there within said first resilient compressible gasket, said fourth recessed area being further recessed from said bottom than said first recessed area and less recessed therefrom than said second recessed area;said fourth recessed area being of a depth from said bottom end that is less than the combined height of said first resilient compressible gasket, said flange of said first metal backshort member and said substrate;said bottom side of said cover plate including a fifth recessed area located within said first recessed area and contiguous to said third recessed area for receiving there within said second resilient compressible gasket, said fifth recessed area being further recessed from said bottom than said first recessed area and less recessed therefrom than said third recessed area;said fifth recessed area being of a depth from said bottom end that is less than the combined height of said second resilient compressible gasket, said flange of said second metal backshort member and said substrate;whereby said cover plate compresses said first and second resilient compressible gaskets against said respective flange of said first and second backshort members when said cover plate is fastened to said metal base plate to press said first and second backshort members against said respective first and second ring frames.