A highly efficient 5.8 GHz CMOS transmitter IC with robustness over PVT variations
ABSTRACT This paper presents a switching PA-based polar transmitter which achieves uniform and robust performances under process, voltage, and temperature variations. A new approach utilizing current driven envelope signal is proposed, leading to much more accurate control of output power of the PA. In addition, the proposed adaptive LO technique extends the available linear control range of the PA. Fabricated in 0.13 um CMOS process, an experimental polar transmitter is designed to fulfill the stringent requirements of the 5.8 GHz Korean DSRC/ETC standards. Delivering output power of + 12 dBm, it consumes average current of 35 mA at 3.3 V supply voltage. Output P-1dB of 15 dBm and ACPR lower than -50 dBc are obtained. The transmitter achieves output power error less than ± 1 dB over the temperature and supply voltage range from -40 to 100°C and from 3.0 to 3.6 V.