Interference Robust Detector-First Near-Zero Power Wake-Up Receiver

Abstract

This paper presents the development of a wake-up receiver (WuRX) at nanowatt power levels for event-driven applications. This paper improves the state of the art, obtaining higher sensitivity than previous work in the 151.8-and 433-bands, low-power operation, and robustness to interference due to an integrated offset compensation algorithm operating without any external calibration. Simultaneous low-power operation and high sensitivity are achieved through a passive detector design based upon a terminal impedance boundary condition-based optimization of the detector dictated by the terminal impedances of the detector. This paper is implemented in a 130-nm CMOS process and obtains −76 dBm at the 151.8-MHz multi-use radio service (MURS) band and −71 dBm at the 433-MHz Industrial, Scientific and Medical (ISM) band with a total dc power draw of just 7.6 nW from 1.0-and 0.6-V supplies. Index Terms-Envelope detector, near-zero-power, ultra-lowpower RF, wake-up receiver (WuRx). I. INTRODUCTION E VENT-DRIVEN smart sensor nodes are an emerging technology platform promising a wide application range ranging from agricultural [1], industrial, infrastructural [2], and perimeter monitoring applications. Event-driven sensor systems spend the majority of their life in an "asleep-yet-aware state" drawing a minimal amount of dc power yet remaining aware of the ambient environment through both ultra-lowpower sensors systems as well as sensing for wake-up events through their WuRx. One major limitation of large-scale smart sensor networks is the impracticability of battery replacement, which drives the need for extremely long sensor lifetimes [3]. Recent advances in near-zero power-level WuRxs [4] have allowed for an extreme reduction in WuRx's power consumption and a significant improvement in the sensitivity of the WuRx front end (see Fig. 1). Still, there is a need for both higher sensitivity and greater robustness to interference in these near-zero power-level receivers.

Tunable, Asynchronous, and Nanopower Baseband Receiver for Charging and Wakeup of IoT Devices

“…Because our design relies on a passive RF front end, the baseband contributes the most to overall current consumption. The baseband's current consumption can be significantly reduced in a fully integrated CMOS implementation [12] [18], which is beyond the scope and objectives of this work.…”

“…The correlator is either permanently powered ON [12]- [20], duty-cycled [6], or placed in a low power mode [21]- [26]. Additionally, a local oscillator generates the clock required for synchronization [6], [12]- [16], [18], [20], [21]. A common baseband implementation is presented in [22], where a microcontroller is used as a bit correlator.…”

Analytical and Experimental Performance Analysis of Enhanced Wake-Up Receivers Based on Low-Power Base-Band Amplifiers

“…The WuRx hardware is generally based on special electronic circuits designed to reduce power consumption without reduction in sensitivity, reliability, and data rate. The hardware design of WuRx can be based on integrated complementary metal-oxide semiconductor (CMOS) circuits [ 21 , 22 , 23 ], where they show a complicated fabrication process that may need a longer development time period within expensive procedures, in contrast to circuits based on COTS components that are usually cheaper in setup, maintenance, expansion, and development. In order to save required energy in listening mode, the WuRx based on COTS uses generally passive components for the continuous listening to the radio channel to activate the MCU [ 24 ].…”

MEES-WuR: Minimum Energy Coding With Early Shutdown for Wake-Up Receivers

“…Wang et al proposed in [22] a WuR based on NCOOK detector consuming 6.1 nW with a sensitivity of -80.5 dBm. Moody et al proposed in [23] a NCOOK WuR achieving a sensitivity of -76 dBm at a frequency of 151.8 MHz, and a bitrate of 200 b/s with a total power consumption of 7.6 nW. Furthermore, Jiang et al proposed in [24] a temperature-robust NCOOK-based WuR consuming 22.3 nW at 9 GHz with a sensitivity of -69.5 dBm and a bitrate of 33.3 b/s.…”