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

A 2-GHz direct conversion receiver for third-generation mobile communicatio ns using wide-band code division multiple access achieves -114-dBm sensitiv ity for 128 kb/s data at 4.096-Mcps spreading rate. The receiver is distrib uted on four dies. The active RC channel selection filter can be programmed to three different bandwidths from 5- to 20-MHz radio-frequency (RP) spaci ng, and the gain control is merged with filtering. RF and baseband chips us e a 25-GHz, 0.35-mu m BICMOS technology while the two analog-to-digital con verters are implemented with a 0.5-mu m CMOS, The double-sideband noise fig ure is 5.1 dB at the 94-dB maximum voltage gain, and the IIP3 and IIP2 are -9.5 and +38 dBm, respectively. The receiver draws 128 mA from a 2.7-V supp ly.