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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.

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In order to solve the problem of actuator failure of flexible joint manipulator, adaptive fault-tolerant control for a flexible manipulator with bounded disturbance is proposed, both actuator partial failure and actuator stuck are considered. The control lows are devised by means of the dynamic surface technique, and the bounded disturbance is compensated via the design of robust items. The stability of the control system is guaranteed via the Lyapunov method. The effectiveness of the theoretical schemes is finally verified by two simulation examples.