Silicon Germanium process technology for wireless Front End Modules and power amplifiers

As consumer wireless protocols increase in complexity (3G and UMTS) and come under intense price pressure, wireless designers are faced with significant challenges to meet overall form factor and cost requirements. Although CMOS base band chips continue down the path of lower cost and smaller form factor, the scaling and cost of Front End Modules (FEMs) and RF transceivers pose a challenge. In a typical 3G WEDGE handset the front end may contain up to 5 discrete power amplifiers, along with an antenna switch and various integrated passives all fabricated in GaAs technology. GaAs based technologies present a barrier to full scale integration of FEMs and transceivers. Silicon Germanium (SiGe) technology facilitates integration of the FEM and radio transceivers, in effect lowering the overall system cost while reducing the form factor. This paper demonstrates the potential of 0.18 mu SiGe based HBTs as an alternative to GaAs.