Design and experiments of transparent rectennas for wireless power harvesting

Abstract

This paper reports the design, optimization and experiments of rectenna circuits, on transparent substrates, dedicated for wireless power harvesting and operating at different frequency bands: GSM, UMTS and Wi-Fi. The proposed circuits are etched on 1.7-mm thickness optically transparent plexiglas, and show more than 95 % transparency. Each circuit contains a linearly-polarized circular loop antenna and a coplanar stripline RF-to-dc rectifier, based on shunt SMS7630 Schottky diode. For 1 µW/cm² (E = 1.94 V/m) power density, the prototypes offer approximately 300, 200, 100 and 100 mV output DC voltage at 940, 1860, 2140 and 2490 MHz, respectively. For the same power density, overall efficiencies of 50, 30, 30 and 25 % were achieved at the same frequencies.Index Terms -rectenna, wireless power harvesting, optical transparency, Schottky diode, RF-to-dc rectifier.

An ultra‐wideband rectenna using optically transparent Vivaldi antenna for radio frequency energy harvesting

“…where V th1 and V th2 are threshold voltages of the diodes D 1 and D 2 , V c2 is the voltage across the capacitor C 2 , and V in is the RF input voltage. 18 The diodes D1 and D2 used in this circuit are Schottky diodes 26 (SMS 7630) due to its low threshold voltage (60-120 mV) and current (0.1 mA). The values of the capacitor C 1 and C 2 are 10 and 100 μF.…”

“…The performance of the rectifier is evaluated from its PCE as shown in (7) η = OutputPower InputPower where η is the efficiency of the rectifier, V out is the output DC voltage, P in is the input power, and R L is the load resistor. 18 The PCE and output DC voltage vary with the change in the output load, frequency, and input power. The change in these parameters will influence a change in the input impedance of the rectifier.…”

Electromagnetic Energy Harvesting Using a Glass Window

“…Po values achieved by EW (from 0.045 to 0.56 mW) are sufficient, by employing an intermittent process, to feed WSNs [3]. For comparison purposes and in order to demonstrate the robustness of the proposed EW, the rectenna presented in [13], which is built on a transparent Plexiglas substrate, is able to provide values of power in the range from 1 to 5000 W.…”

MEMS Based RF Energy Harvester for Battery-Less Remote Control: A Review

“…RF-DC conversion efficiency is affect by input impedance mismatching and diode losses. However, the diode losses are typically dominant (Bellal et al, 2016). A lower built-in voltage for a diode would realize a higher rectifying efficiency.…”