A Fully-Integrated Ambient RF Energy Harvesting System with 423-μW Output Power

Abstract

This paper proposes a 2.4-GHz fully-integrated single-frequency multi-channel RF energy harvesting (RFEH) system with increased harvested power density. The RFEH can produce an output power of ~423-μW in harvesting ambient RF energy. The front-end consists of an on-chip impedance matching network with a stacked rectifier concurrently matched to a 50 Ω input source. The circuit mitigates the “dead-zone” by enhancing the pumping efficiency, achieved through the increase of Vgs drivability of the proposed internal gate boosting 6-stage low-input voltage charge pump and the 5-stage shared-auxiliary-biasing ring-voltage-controlled-oscillator (VCO) integrated to improve the start-up. The RFEH system, simulated in 180-nm complementary metal–oxide–semiconductor (CMOS), occupies an active area of 1.02 mm2. Post-layout simulations show a peak power conversion efficiency(PCE) of 21.15%, driving a 3.3-kΩ load at an input power of 0 dBm and sensitivity of −14.1 dBm corresponding to an output voltage, Vout,RFEH of 1.25 V.

Evolution of Bioamplifiers: From Vacuum Tubes to Highly Integrated Analog Front-Ends

“…Solutions allowing a radio-frequency energy-harvesting (RFEH) system with an increased harvested power density can also be added here. Nowadays, RFEH systems can produce an output power of ~423 µW for harvesting ambient RF energy [190], which provides excellent prospects for the development of wearable devices for biopotential recording.…”

Reconfigurable Antennas for RF Energy Harvesting Application: Current Trends, Challenges, and Solutions from Design Perspective

“…The advanced feature of these reconfigurable antennas is the maximization of wireless communication through the integration of many radios onto a single platform. Due to their ability to operate over a broad frequency range, modify their geometries, and adapt to changes, reconfigurable antennas are therefore being viewed as a practical solution to cover the variety of wireless services [74][75][76][77]. There are several reconfiguration properties: frequency reconfigurability [78][79][80][81], polarization reconfigurability [82][83][84][85], pattern reconfigurability [86][87][88][89], hybrid reconfigurability [90][91][92][93], electrical diversity [94][95][96][97], optical diversity [98][99][100][101], mechanical diversity [102][103][104][105], material diversity [106][107][108][109], etc.…”

A Subthreshold Operation Series-Parallel Charge Pump Incorporating Dynamic Source-Fed Oscillator for Wide-Input-Voltage Energy Harvesting Application

“…A ring voltage-controlled oscillator (RVCO) is a key block in the clock generation unit in the CP scheme to generate an oscillating clock signal [35], [36], [37], [38]. The generated oscillating frequency is dependent on the number of inverter cells and the delay time, as shown in the equation below [39] and [40]:…”

“…The oscillating frequency can be reduced by increasing the number of delay cell stages or by reducing the oscillator's input voltage (V OSC ). However, increasing the number of delay cell stages is not a suitable method for frequency regulation as it will increase the oscillator's power consumption, which can be discernible from the equation below [39]:…”