ADF4602:  Single-Chip, Multiband 3G Femtocell Transceiver

The ADF4602 is a 3G transceiver integrated circuit (IC) offering unparalleled integration and feature set. The IC is ideally suited to high performance 3G femtocells providing cellular fixed mobile converged (FMC) services. With only a handful of external components, a full multiband transceiver is implemented.

UMTS Band 1 through Band 6 and Band 8 through Band 10 are supported in a single device.

The receiver is based on a direct conversion architecture. This architecture is the ideal choice for highly integrated wideband CDMA (WCDMA) receivers, reducing the bill of materials by fully integrating all interstage filtering. The front end includes three high performance, single-ended low noise amplifiers (LNAs), allowing the device to support tri-band applications. The single-ended input structure eases interface and reduces the matching components required for small footprint single-ended duplexers. The excellent device linearity achieves good performance with a large range of SAW and ceramic filter duplexers.

The integrated receive baseband filters offer selectable bandwidth, enabling the device to receive both WCDMA and GSM-EDGE radio signals. The selectable bandwidth filter, coupled with the multiband LNA input structure, allows GSM-EDGE signals to be monitored as part of a UMTS home basestation.

The transmitter uses an innovative direct conversion modulator that achieves high modulation accuracy with exceptionally low noise, eliminating the need for external transmit SAW filters.

The fully integrated phase lock loops (PLLs) provide high performance and low power fractional-N frequency synthesis for both receive and transmit sections. Special precautions have been taken to provide the isolation demanded by frequency division duplex (FDD) systems. All VCO and loop filter components are fully integrated.

The ADF4602 also contains on-chip low dropout voltage regulators (LDOs) to deliver regulated supply voltages to the functions on chip, with an input voltage of between 3.1 V and 3.6 V.

The IC is controlled via a standard 3-wire serial interface with advanced internal features allowing simple software programming. Comprehensive power-down modes are included to minimize power consumption in normal use.

Applications

• 3G home basestations (femtocells)