IJSRP, Volume 4, Issue 2, February 2014 Edition [ISSN 2250-3153]
Mr. P. J. Sonawane, Prof. A. B.Sapkal
This paper shows far-field wireless powering for low-power wireless sensors. Sometimes in many applications where the sensors are used, is difficult or impossible to change the batteries of sensor unit because we don’t know the exact position of the sensors or sensors are mobile. Here expected radio-frequency (RF) power densities is in the range of 20–200-µW/cm2, overall size of sensor is small which transmit data at low duty cycles. For these type of applications low-power nondirective wireless powering is appropriate for sensors. The power is provided to the sensor platform through an antenna which receives incident electromagnetic waves in the gigahertz frequency range. This antenna gives the energy to a rectifier circuit which charges a storage device (e.g., thin-film battery) through an efficient power management circuit. The entire platform, including sensors and a low-power wireless transmitters are controlled through a low-power microcontroller.