Designing a single-chip, six-band UMTS transceiver for world-wide wireless connectivity

The UMTS (Universal Mobile Telecommunications System) is one of the technologies emerging for the third-generation (3G) mobile communications system that is being developed as a successor to the existing GSM system. UMTS has become a truly global standard, with different frequency bands specified to completely cover requirements in Europe, Asia, North America and Japan. To take advantage of this technology, the designers of UMTS mobile phones are increasingly calling for multi-band support to allow global roaming, more features and faster data transmission rates, along with smaller and significantly less expensive components. This presents a real challenge for all communications semiconductor suppliers.

To meet this challenge, chip designers are focusing on three major features when designing their next-generation RF (radio frequency) transceivers: small size, low power consumption and support for multi-frequency bands. Creating such a solution requires integrating a true multi-band capability into a single chip, including an adaptive receive baseband filter, fully integrated fractional-N PLLs for both transmission and reception, and multiple, flexibly programmable front-end control. Additionally, the manufacturing process for the chip should be one that results in a footprint that meets the extremely compact cellular phone form factor requirements.

The ideal solution is a single-chip, low-power CMOS RF transceiver that supports all the UMTS frequency bands currently specified within the WCDMA (Wideband Code Division Multiple Access)-based UTRA FDD (UMTS Terrestrial Radio Access Frequency Duplex Division) access scheme. UMTS phones incorporating such a chip would be able to be used in Europe, Asia, North America and Japan, ensuring easy access in the areas of the world currently most widely served by cellular services.