A fully integrated 2.4-GHz CMOS diversity receiver with a novel antenna selection

Abstract

A new low-complexity antenna diversity architecture, using a 2.4-GHz single low-IF receiver chain with a novel antenna selection scheme, is exploited by using 0.18-µm CMOS technology. The receiver has been developed for the IEEE standard 802.15.4 radio system and two RF input channels are selected through an efficient analog-type antenna selection scheme for achieving the diversity. Compared to conventional receivers without diversity, 10∼15 dB improvement of the received signal strength (RSS) has been measured for non-line-of-sight (NLOS) channels. By incorporating a wake-up function for the baseband blocks, the receiver operates at a very low power of 8.5 mW, with a 1.8 V power supply in the standby mode for receiving. The antenna selection error is negligible (≪1 %) and the antenna selection time is very fast (≪20 µs).