Acoustic FBAR for filters, duplexers and front end modules

Abstract

Agilent first proposed using FBAR for CDMA PCS duplexers in 1999. The first commercial product was offered in 2001. Since then, Agilent's share of PCS duplexer "phone slots" has increased from thousands per month to millions per month. The number of design wins in new phones surpassed 60 by Fall of 2003 and continues to grow. The first commercialized FBAR PCS duplexer, used two FBAR die (Rx and Tx) packaged into two LCC packages and then mounted on a small, pc board. The next generation duplexer uses a wafer-scale chip package or "microcap" process. Microcap allows the ability to do direct die on board and not be concerned about hermetic or mechanical issues. This new technology then allows one to both reduce cost and size of the duplexer. It also allows for the integration of both duplexers and point filters into Front End Modules (FEM). The high-Q, excellent acoustic coupling of FBAR and the ability to microcap our die open up the possibility to enter into other duplexer markets besides PCS. Currently, we are investigating microcap'd duplexers for WCDMA, Cell band CDMA and Korean CDMA bands. When combined with Agilent's EPHEMT technology for Power Amplifiers, Front-End Modules can be designed for optimum performance and size.