Digital-IF WCDMA handset transmitter IC in 0.25 /spl mu/m SiGe BiCMOS

This paper describes a 1.8/spl times/2.2 mm/sup 2/ WCDMA handset transmitter IC which reduces power consumption by employing a high-order-hold DAC, an adaptively-biased mixer, and an RF VGA. Implemented in a 0.25 /spl mu/m SiGe BiCMOS process, the IC consumes 58 mA at maximum output power of 3.5 dBm, and 41 mA at reduced output from a 3 V supply.