Dual band harvester architecture for autonomous remote sensors

In this work we present a high dynamic range and high efficiency energy harvesting system for low power sensors architecture. This system constitutes an autonomous device potentially showing an infinite lifelong cycle of use. The designed circuit has been conceived as a dual band architecture able to capture the largest amount of EM radiation in the urban or indoor environment, since the receiver is tuned at both GSM and WiFi frequencies. The harvester power battery loading circuitry is also available on board and guarantees the required energy for the autonomous sensor to work. The system handles an incoming power typically ranging from −20 dBm to 20 dBm and rectifies the variable input signals into a DC voltage source with a high conversion efficiency. Theoretically speaking the rectified power is greater than 50% for an incoming power between −5 dBm and 15dBm. Test measurements of the proposed system succeeded with compliant results. As a typical applications load, we have considered a commercial gas sensor, for Carbon Dioxide (CO2) detection, so proving the system capability to be employed in wireless sensors networks. The whole system, designed as discrete element board, has been conceived in order to be completely integrated in a standard CMOS technology.