Analog Devices unveiled the latest addition to its family of Othello 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. 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.

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. Othello-3 (AD6551) is sampling now in a 6 mm x 6 mm 40-lead lead-frame chip scale package.