Patent ID: 7602263
Filing Date: 2009-10-13
Classification: H03H,Y10T

Abstract:
1. A surface acoustic wave (SAW) duplexer comprising: a transmitting SAW filter having a first input portion and a first output portion; a receiving SAW filter having a second input portion and a second output portion; a single piezoelectric substrate on which the transmitting and receiving SAW filters are formed, wherein the single piezoelectric substrate has first and second sides which face each other; a package base board on which the single piezoelectric substrate is mounted; an input terminal which is positioned on the package base board and outside the single piezoelectric substrate; an output terminal which is positioned on the package base board and outside the single piezoelectric substrate; a first interconnection line which is directly connected with the first output portion of the transmitting SAW filter and which is electrically connected to the output terminal of the package base board; and a second interconnection line which is directly connected with the second input portion of the receiving SAW filter and which is electrically connected to the input terminal of the package base board, wherein the first output portion of the transmitting SAW filter is positioned closer to the first side than the second side of the single piezoelectric substrate, and the second input portion of the receiving SAW filter is positioned closer to the second side than the first side of the single piezoelectric substrate, wherein the first input portion of the transmitting SAW filter is positioned closer to the second side than the first side of the single piezoelectric substrate, and the second output portion of the receiving SAW filter is positioned closer to the first side than the second side of the single piezoelectric substrate, wherein both of the input and output terminals are electrically connected to an antenna, wherein the output portion of the transmitting SAW filter is positioned away from the input portion of the receiving SAW filter on the single piezoelectric substrate, and wherein the first and second interconnection lines extend each other in different directions.