International audienceThe aim of this paper is to show the possibility to harvest Radio Frequency (RF) energy to supply Wireless Sensor Networks (WSNs) in outdoor environment. In those conditions, the number of existing RF bands is unpredictable. The RF circuit has to harvest all the potential RF energy present and cannot be designed for a single RF tone. In this paper, the designed RF harvester adds powers coming from an unlimited number of sub-frequency bands. The harvester's output voltage ratios increase with the number of RF bands. As an application example, a 4-RF band rectenna is designed. The system harvests energy from GSM900 (Global System for Mobile Communications), GSM1800, UMTS (Universal Mobile Telecommunications System) and Wi-Fi bands simultaneously. RF-to-dc conversion efficiency is measured at 62% for a cumulative -10 dBm input power homogeneously widespread over the four RF bands and reaches 84% at 5.8 dBm. The relative error between the measured dc output power with all the 4 RF bands ON and the ideal sum of each of the four RF bands power contribution is less than 3%. It is shown that the RF-to-dc conversion efficiency is more than doubled compared to that measured with a single RF source, thanks to the proposed rectifier architecture
International audienceWe report on a new topology of coupling between substrate integrated circular cavities designed to produce particular filtering functions through combination with the classical iris-based coupling. This coupling is achieved by a grounded coplanar line etched at the top of cavities. This topology was used to realize a Ku-Band third-order filter, whose synthesis, electromagnetic simulation with HFSS, and experimental performances are presented here
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