Abstract—In this paper, an approach to map the Bluetooth and 802.11b standards specifications into an architecture and specifications for the building blocks of a dual-mode direct conversion receiver is proposed. The design procedure focuses on optimizing the performance in each operating mode while attaining an efficient dual-standard solution. The impact of the expected receiver nonidealities and the characteristics of each building block are evaluated through bit-error-rate simulations. The proposed receiver design is verified through a fully integrated implementation from lownoise amplifier to analog-to-digital converter using IBM 0.25m BiCMOS technology. Experimental results from the integrated prototype meet the specifications from both standards and are in good agreement with the target sensitivity. Index Terms—802.11b, BiCMOS integrated circuits, Bluetooth (BT), direct conversion, radio receivers, system-level design, Wi-Fi.