A 2.4-GHz CMOS Driver Amplifier Based on Multiple-Gated Transistor and Resistive Source Degeneration for Mobile WiMAX

A CMOS driver amplifier employs two design techniques to improve its linearity in wide output power level. First, multiple-gated transistor (MGTR) technique with two auxiliary transistors extends the linear region further compared with MGTR with single auxiliary transistor. Second, resistive source degeneration significantly suppresses the unwanted 2^nd-harmonic feedback effect caused by an inductive source degeneration. A 2.4-GHz differential driver amplifier has been implemented in 0.18 mum CMOS for Mobile WiMAX and Korean WiBro applications. It shows that the linear region with OIP3 of >+20dBm is extended up to an output power of -5 dBm, while achieving a maximum OIP3 of +28 dBm, OPldB of +7.8 dBm, and a power gain of 9.2 dB with dc power consumption of 1.8V and 18.7 mA.