A CMOS 868/915 MHz direct conversion. ZigBee single-chip radio

In this article the 868/915 MHz radio transceiver specifications have been derived for IEEE 802.15.4, a low-rate, low-cost, and low-power network standard. The radio specifications include parameters such as noise figure, nonlinearity, channel filtering, phase noise of local oscillator, dynamic range, and bit resolutions of analog-to-digital and digital-to-analog converters. Based on a direct conversion scheme, top-down system-level performance analyses using the radio specifications are realized. Low-power and low-cost circuit topologies are also discussed with chip implementations using 0.18 pm CMOS technology.