Spyridon-Nektarios Daskalakis

TL;DR: In this article, a single-series circuit with one double diode on a low-cost, lossy FR-4 substrate was proposed for RF energy harvesting, where rectennas were connected in series configuration (voltage summing), forming rectenna arrays.

TL;DR: In this article, a low-cost (6 Euro per sensor), low-power (in the order of $200~\mu \text{W}$ per sensor) with high communication range (on the order to 250 m), scatter radio sensor network is presented, for soil moisture monitoring at multiple locations.

Abstract: Nowadays the measurement of moisture level in plants is critical for agriculture. One way to detect this is to measure the temperature difference between the leaf and the air. This paper introduces a novel wireless leaf temperature sensor that utilizes ambient FM backscattering for smart agricultural applications. The sensor is based on an ultra low power micro-controller, a sensor board and a RF front-end for wireless communication. The sensor communicates using backscatter radio principles on ambient FM station signals using AM modulation with FM0 encoding. The prototype featured an effective operation up to ranges of 0.5 m by backscattering sensor information at 50 bps and 500 bps using an ambient FM radio signal inside a laboratory setup. A high percentage of bits was clearly visible up to 2 m at 50 bps.

TL;DR: In this article, the authors studied whether increased ranges of bistatic scatter radio communication are possible, especially when low-cost, embedded receivers, originally designed for conventional radio (and not for scatter radio) are employed.

TL;DR: An efficient, low-cost and low-complexity rectenna-grid is analyzed, fabricated and measured, for low-power RF input and RF density and Measurements of the proposed RF harvester agree well with simulations.