Above-IC FBAR technology for WCDMA and WLAN applications

Abstract

This paper demonstrates the feasibility of an above- IC bulk acoustic wave technology for wireless applications in the 2 to 6 GHz frequency range. BAW filters with balanced input and output have been integrated as a post-process directly above BiCMOS wafers comprising RF circuits. A double-lattice filter designed for 2.14 GHz W-CDMA and featuring insertion loss of - 3dB and extreme out-of-band rejection (>-50dB) is used in a simplified RF front-end receiver. A single lattice version has been designed for WLAN applications, and features insertion loss of - 2dB at 5.4 GHz.