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

V.W. Leung, L.E. Larson, P.S. Gudem
2004 IEEE Journal of Solid-State Circuits  
Implemented in a 0.25-m SiGe BiCMOS process, a highly integrated low-power transmitter IC (TxIC) is developed for wideband code-division multiple-access handset applications. Based on a digital-IF heterodyne architecture, it eliminates the external IF surface acoustic wave filter by adopting a meticulous frequency plan and a special-purpose second-order-hold D/A conversion scheme. The TxIC features a low-power high-speed D/A converter designed to drive a dominantly capacitive load. For the
more » ... version mixer and the RF amplifier, adaptive biases are designed to minimize the quiescent power consumption and to provide current boost only when needed. The TxIC achieves 1% EVM. It consumes 180 mW (3-V supply) for the maximum output power of +5 dBm and reduces to 120 mW during power backoff. Index Terms-Digital-IF, digital-to-analog converter (DAC), heterodyne, high-order hold, mixer, RF amplifier, SiGe, singlesideband (SSB), transmitter, wideband code division multiple access (WCDMA).
doi:10.1109/jssc.2004.836337 fatcat:h5njdifrrvhujlwoyjabfamhmm