Radio transceivers for wireless personal area networks using IEEE802.15.4

This article describes the design considerations for low-power short-range radio transceivers with a focus on the 2.4 GHz PHY layer defined as part of the IEEE 802.15.4 standard. The specification requirements for IEEE 802.15.4-compliant transceivers, and the design challenges and practical implementation of a highly-integrated low-power 2.4 GHz transceiver are subsequently discussed. The transceiver uses a direct-conversion receiver with switched antenna diversity and a transmitter using direct closedloop VCO modulation. It integrates a mask-programmable radio controller capable of autonomously performing timing-critical MAC functions, and a sleep timer. Implemented in 0.18 mum RFCMOS technology with a chip area of less than 6 mm², the transceiver achieves a link margin of 99 dB while drawing 16.8 mA and 18 mA from a 1.8 V supply in receive and transmit mode, respectively.