Patent ID: 7684764

Claim:
A duplexer comprising: transmit and receive surface acoustic wave (SAW) filters having different center frequencies, the transmit SAW filter being connected between a transmit terminal and a common terminal, the receive SAW filter being connected between a receive terminal and the common terminal; a phase matching circuit that matches phases of the two SAW filters; a package in which the SAW filters and the phase matching circuit are housed, the package being composed of multiple layers; and a line pattern provided between the receive SAW filter and the receive terminal, the line pattern running on at least two of the multiple layers within a range defined by horizontally opposing ground patterns provided on a surface of a layer of the multiple layers, a part of the line pattern running on the surface of the layer, said range being defined between a side of an opening of the package in which the SAW filters are housed and a corresponding outer side of the package.