Patent ID: 7180387

Claim:
An antenna duplexer comprising a package ( 83 ) having a plurality of ceramic layers ( 81 ) superposed, and a transmitting filter ( 51 ) and a receiving filter ( 41 ) which are mounted on a surface of the package ( 83 ), a phase-matching strip line ( 7 ) being formed on a surface of at least one ceramic layer ( 81 ) providing the package ( 83 ), grounding layers ( 61 ), ( 71 ) being formed respectively on surfaces of upper and lower ceramic layers ( 81 ), ( 81 ) of the package ( 83 ) with the phase-matching strip line ( 7 ) interposed therebetween, a plurality of conductor lines being formed around the phase-matching strip line ( 7 ) for connecting the two grounding layers ( 61 ), ( 71 ) to each other, the plurality of conductor lines being electrically separated from each other on the surface of the ceramic layer ( 81 ) formed with the phase-matching strip line ( 7 ).