Investigation of SAW W-CDMA antenna duplexer and GSM-based FEM including duplexer

GSM/W-CDMA dual-mode phones will be required in Europe and elsewhere. Therefore, we must not only develop a SAW antenna duplexer for W-CDMA but also combine the duplexer with a GSM-based SAW FEM (front-end module). First, we show characteristics of a W-CDMA duplexer developed using conventional hybrid-ceramics multi-layered technologies. Next, we investigate configurations of the GSM-based FEM which includes the W-CDMA duplexer. We also examine the non-linear characteristics of the SAW duplexer, because very high off-band blocking characteristics are required by 3GPP specifications. Not only performance improvement of the SAW filters but also miniaturization of the duplexer are presented to achieve the future multi-band/multi-mode FEMs.