A dual-band high efficiency CMOS transmitter for wireless CDMA applications

Abstract

A dual-band transmitter integrated circuit (TxIC), including baseband filter and variable gain amplifier (VGA), upconverter, RF VGA, driver amplifier (DA), is implemented in 0.18 mum CMOS for CDMA applications. The TxIC increases the handset talk time dramatically with the PA-bypass feature. The chip provides more than a total power control range of 80 dB and a fine gain step of 0.25 dB/LSB. The chip achieves 52.3 dBc ACPR at +7 dBm output power with 52.2 mA and 51.7 dBc ACPR at +7 dBm output power with 51.9 mA for low band and high band applications respectively.