Analog Devices Demonstrates new RF transceivers for WiMAX certified terminals

Leveraging ADI's data conversion and RF signal processing expertise, the new transceivers integrate high-performance data converters on chip and deliver outstanding RF performance, enabling a WiMAX terminal solution that meets the reduced cost requirements essential for high volume deployment. Excellent RF performance ensures expanded coverage and improved service quality--factors that enhance the user experience and help to facilitate consumer adoption.

Unlike conventional solutions that implement the analogue functions on separate devices or include the data converters on the ASIC, the AD9352 and AD9353 RF transceivers utilise "smart-partitioning," a concept pioneered by ADI, to integrate all the analog signal processing technology--analogue-to-digital converters (ADCs), digital-to-analogue converters (DACs), and RF functions--on a single chip. This allows the digital baseband chips to be manufactured on more cost-effective fine line processes, such as 90 nm or 65 nm. The transceivers feature a direct connection to the digital modem via the ADI/Q(TM) digital I/Q interface, a simple parallel CMOS digital I/O interface that has been adopted by multiple digital modem partners.

"ADI is the first company to introduce RF CMOS direct conversion WiMAX transceivers that combine high integration with high performance, and offer the ADI/Q digital I/Q interface for a seamless connection to the digital baseband," said Bernard Aboussouan, VP, marketing and business development for Sequans Communications, a leading supplier of fixed and mobile WiMAX silicon and software. "We chose to partner with ADI and implement the ADI/Q digital interface on our SQN1110 802.16e compliant digital baseband. We are confident that ADI's WiMAX transceivers combined with our digital baseband will offer a solution that meets the price, performance and time-to-market requirements of WiMAX terminal manufacturers."

"WiMAX continues to gain industry support, with recent commitments by worldwide and North American carriers to build-out a nationwide WiMAX network," said Dave Robertson, product line director, High Speed Signal Processing Group, Analog Devices. "By introducing products like the AD9352 and AD9353 transceivers, Analog Devices is helping to facilitate the mass deployment of WiMAX and reduce the barriers to cost and performance."

Highly-Integrated RF Transceivers
The AD9352 and AD9353 are fully-integrated, direct conversion transceivers for WiMAX (IEEE 802.16) wireless network systems that offer a complete RF and mixed-signal system on a chip. The dual-band AD9352 operates in the 2.3 to 2.7 GHz and 4.9 to 5.9 GHz ranges and the single-band AD9353 operates in the 3.3 to 3.8 GHz range. Together, the transceivers cover most licensed and unlicensed bands worldwide.

Integrated on the transceivers are 12-bit, 160 mega-samples-per-second (MSPS) ADCs and DACs, along with smart system features such as self-calibration, automatic gain control, transmit power control, support for automatic frequency control, and auxiliary ADCs and DACs for system monitoring. The on-board converters and smart system features reduce the required level of real time signal processing between modem and the transceiver, thus dramatically simplifying RF driver development and support. The transceivers also integrate a high sensitivity direct-conversion CMOS receiver, and channel-select filtering at baseband. A low phase noise LO path is achieved by integrating a fractional-N synthesizer. To reduce system cost, an on-chip crystal oscillator replaces the expensive voltage controlled temperature compensated crystal oscillator (VCTCXO).

Superior RF Performance The devices offer excellent noise figure of 3.5 dB along with adjacent channel and alternate channel rejection capability that is 8 dB higher than the 802.16 standard requires. The devices' highly linear transmit path has excellent spectral purity and offers error vector magnitude (EVM) of -37 dB at 0 dBm output power. The transmit power is detected by an accurate power detector and autonomously controlled with a range of 60 dB with step increments of 0.25 dB.

The AD9352 and AD9353 are sampling now with full production scheduled for December 2006. The transceivers, priced starting at $14.95 per unit in 1,000-piece quantities, are available in 9 mm x 9 mm 64-pin lead free chip scale packages (LFCSP), and are specified over an operating temperature range of -40 degrees C to +85 degrees C. An evaluation board is available.