CMOS high linearity PA driver with an on-chip transformer for W-CDMA application

A fully integrated high linearity differential power amplifier driver with an on-chip transformer in a standard 0.13-μm CMOS process for W-CDMA application is presented.The transformer not only accomplishes output impedance matching,but also acts as a balun for converting differential signals to single-ended ones.Under a supply voltage of 3.3 V,the measured maximum power is larger than 17 dBm with a peak power efficiency of 21％.The output power at the 1-dB compression point and the power gain are 12.7 dBm and 13.2 dB,respectively.The die size is 0.91 × 1.12 mm2.