All-CMOS radio transceivers and systems-on-a-chip are rapidly making inroads on a wireless market that for years was dominated by bipolar and BiCMOS solutions. It is not a matter of replacing bipolar transistors in known circuit topologies with FETs; the wave of RF-CMOS brings with it new architectures and unprecedented levels of integration. What are its origins? What is the commercial impact? How will RF-CMOS evolve in the future? This paper offers a retrospective and a perspective.