The integration level of RFICs has exhibited considerable progress during the last decade. Si-based single-chip GSM, Bluetooth and DECT transceivers have been reported, while the most exciting milestone for integration will be the RF-system-on-a-chip (i.e., "RF-SoC") product for single-chip multiband multi-standard cellular ICs that support broadband communication. To achieve this highest level of RFIC integration, one has to choose a radio system architecture that requires a minimal number of external components, together with a judicious selection of the IC technology for implementation. For example, we anticipate the direct-conversion or a robust low-IF receiver architecture to become the dominant choice for 3G handset applications. We also expect the Si/SiGe BiCMOS technology to be the optimal device technology for implementing low-power cellular RF-SoC products, while RF-CMOS technology will probably be most successful for the low-cost, less performance sensitive Bluetooth and/or wireless LAN applications.