An RF energy harvesting power management circuit for appropriate duty-cycled operation

Abstract

In this study, we present an RF energy harvesting power management unit (PMU) for battery-less wireless sensor devices (WSDs). The proposed PMU realizes a duty-cycled operation that is divided into the energy charging time and discharging time. The proposed PMU detects two types of timing, thus, the appropriate timing for the activation can be recognized. The activation of WSDs at the proper timing leads to energy efficient operation and stable wireless communication. The proposed PMU includes a hysteresis comparator (H-CMP) and an RF signal detector (RF-SD) to detect the timings. The proposed RF-SD can operate without the degradation of charge efficiency by reusing the RF energy harvester (RF-EH) and H-CMP. The PMU fabricated in a 180 nm Si CMOS demonstrated the charge operation using the RF signal at 915 MHz and the two types of timing detection with less than 124 nW in the charge phase. Furthermore, in the active phase, the PMU generates a 0.5 V regulated power supply from the charged energy.

InGaAs-based planar barrier diode as microwave rectifier

“…1(a)] to vary the energy barrier and observed the effects on the electrical behavior of the PBD. Based on these results, we employed the best structural parameters of the PBD to analyze the curvature coefficient γ by dividing the second differential of the I-V characteristics by its first differential ( f (2) =f (1) ) 29) in order to evaluate the conversion efficiency of the rectification process in the device. A sinusoidal transient analysis with an amplitude of 0.1 V and DC bias voltage of 0.05 V then was conducted to observe the rectification performance at various frequencies.…”

“…Recently, with the emerging interest in Internet of Things (IoT) technology, focus on the improvement of wireless communication systems has increased. Radio frequency identification systems and energy harvesting from the surrounding electromagnetic waves (RF harvesting) [1][2][3] have been gaining attention as a longer power transfer distance can be achieved with their application. 4) Emitters and detectors in this system should be capable of operating efficiently at high-frequency ranges to ensure high-quality signals.…”

Influence of design parameters on performance of piezoelectric MEMS energy harvesting

“…7) Manually replacing batteries for the numerous sensors is unrealistic in terms of cost. Energy harvesting from ambient energy such as vibration, 8) heat transfer, 9) radiowaves, 10) and light 11) has been investigated in the last few decades. Mechanical vibration is a promising energy source for IoT devices located on movable parts.…”