A Clock-Harvesting Receiver Using 3G CDMA Signals in the 1900-MHz Band

A clock-harvesting receiver is presented, which extracts a 1.2-kHz clock embedded within the third-generation code-division multiple-access standard for the wake-up of a wireless sensor network. The energy-detection-based receiver was fabricated in 0.13-μm CMOS and designed for low-power heavily duty-cycled operation. In active mode, the receiver has a measured sensitivity of -73 dBm while consuming only 298 μW. The harvested-clock output has 7 μs of root-mean-square jitter at the sensitivity level, which improves with higher received power. In sleep mode, the receiver consumes only 44 pW with a start-up time of 80 μs.