Be flexible

The first section of this article gives an overview of standards that current multimode cellular phones must support. The paper then covers traditional analog architectures that were dominant in the SiGe-BiCMOS era and were also the basis for the first CMOS-based transceivers. Then the paper focuses on the extension to these architectures utilizing digital front-ends (DFEs) to enhance their flexibility and configurability. The final section gives an outlook to upcoming developments for CMOS nodes beyond 130 nm like all-digital phase locked loops (ADPLL) and sampling receivers.