CMOS RF transceiver is a complete solution for 3G mobile terminals based on W-CDMA
Analog Devices has unveiled the latest addition to its family of Othello(R) radios, the Othello-3. This CMOS RF transceiver provides a complete solution for 3G mobile terminals based on the W-CDMA air interface standard. Leveraging ADI's Othello direct-conversion architecture and an innovative low-noise transmitter, the Othello-3 (AD6551) transceiver eliminates the need for transmit-path surface acoustic wave (SAW) filters. In addition to simplifying the RF section in 3G mobile terminals, Othello-3 reduces board space by 40 percent over competing solutions – key drivers to delivering smaller, more cost-effective 3G handsets.
Following on the success of our Othello-G chipset, which significantly decreased the size of the radio in GSM/GPRS, we are now able to reduce board space in W-CDMA terminals to a mere 5 square centimeters – less than one square inch, said Christian Kermarrec, vice president, RF and Wireless Systems, Analog Devices, Inc. Our innovative technique to reducing the component count of a typical RF front end translates into lower cost, easier to implement solutions, thereby driving the proliferation of highly-integrated, feature-rich, W-CDMA handsets.
According to research and consulting firm Strategy Analytics, the worldwide market for W-CDMA handsets is expected to nearly double, from 90 million units to 161 million units in 2007.
Othello-3 expands ADI's portfolio of award-winning direct-conversion radios, which includes Othello-E (supporting EDGE) and Othello-G (supporting GSM/GPRS). Othello-3 supports full quad-band operation and integrates virtually all the necessary components for a complete cellular handset radio design, such as voltage-controlled-oscillators and the associated tank circuits, loop filters and power management circuitry. The device also features a low-noise transmitter architecture, eliminating the need for transmit-path SAW filters, which are usually needed to prevent transmitter noise from interfering with the receiver in full-duplex operation. In doing so, Othello-3 significantly reduces cost and board space compared to existing RF transceiver solutions and complements the Analog Devices SoftFone-W baseband chipset for W-CDMA handsets.
The Othello-3 transceiver provides a complete transmit/receive solution for W-CDMA-based mobile terminals. The receiver section includes high-performance single-ended low-noise amplifiers for two high bands (1710 MHz to 2170 MHz) and one low band (824 MHz to 960 MHz). Direct-downconverting quadrature mixers driven by an on-chip fractional PLL synthesizer deliver baseband in-phase and quadrature signals to a variable-gain amplifier (VGA) and programmable low-pass filter stages with dc offset correction.
The transmitter section consists of a fractional PLL synthesizer, high performance VGAs and quadrature modulators for high- and low-band outputs, as well as a root-mean-square (rms) RF power detector and on-chip digital-to-analog converter (DAC) for power amplifier control.
According to the company, Othello-3 (AD6551) is sampling now in a 6 mm x 6 mm 40-lead lead-frame chip scale package.