An analog baseband circuitry for a WCDMA direct conversion receiver

An analog baseband circuitry for a WCDMA direct conversion receiver is described. The circuitry includes a channel selection filtering and amplification with an adjustable gain in a merged manner. The active RC technique is applied. The filter bandwidth can be set to 2MHz, 4MHz or 8MHz and the gain can be controlled from -9dB to 69dB in 3dB steps. The filter frequency response is tuned with binary weighted switchable capacitor matrices. At the 2MHz bandwidth the chip consumes 39mA from a 2.7V supply. The chip has been fabricated with a 0.35µm BiCMOS process.