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

A dual-band transmitter integrated circuit (TxIC), including baseband filter and variable gain amplifier (VGA), upconverter, RF VGA, driver amplifier (DA), is implemented in 0.18um 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 80dB and a fine gain step of 0.25dB/LSB. The chip achieves 52.3dBc ACPR at +7dBm output power with 52.2mA and 51.7dBc ACPR at +7dBm output power with 51.9mA for low band and high band applications respectively.