A 2-GHz wide-band direct conversion receiver for WCDMA applications

A 2-GHz direct conversion receiver for third-generation mobile communications using wide-band code division multiple access achieves -114-dBm sensitivity for 128-kb/s data at 4.096-Mcps spreading rate. The receiver is distributed on four dies. The active RC channel selection filter can be programmed to three different bandwidths from 5 to 20-MHz radio-frequency (RF) spacing; and the gain control is merged with filtering. RF and baseband chips use a 25-GHz, 0.3-/spl mu/m BiCMOS technology while the two analog-to-digital converters are implemented with a 0.5-/spl mu/m CMOS. The double-sideband noise figure is 5.1 dB at the 94-dB maximum voltage gain, and the IIP3 and ITP2 are -9.5 and +38 dBm, respectively, The receiver draws 128 mA from a 2.7-V supply.