The new millennium: wireless technologies for a truly mobile society

摘要

Universal access to a wide range of telecommunication services, from speech over multimedia to navigation and mobile computing, must be provided for the mobile society of the next millennium. The backbone of this scenario is a worldwide high-bandwidth wireless system. The wireless terminals of the next millennium, comprising all conceivable services in small size with long operating time require significant improvements in all underlying technologies as well as new architectures and new development strategies and design tools. The computing power needed from several tens of millions transistors at high clock rates requires new approaches simultaneously to allow maximum performance and minimum leakage current. Revived conversion principles like direct downconversion start to be seen in volume production. These concepts put most selection into baseband, avoiding a SAW filter and drastically reducing the number of RF blocks. Power amplifiers still use expensive GaAs HBTs. New concepts will improve power-added efficiency and give GaAs a push. For low-transmit-power applications, silicon PAs with higher performance and lower cost soon will be feasible. MEMS technologies will allow integration of mechanical antenna switches as well as other discrete RF circuitry. The remaining discretes will be integrated by advanced packaging technologies such as subsystem assembly, multi-chip or system module packages. With present growth rates, the sales of wireless terminals will exceed those of computers and internet nodes. These terminals will drive CMOS technology.