A backscatter modulation radio-frequency (RF) sensor and method for using the same are disclosed herein. In one embodiment, the RF sensor comprises: an energy harvesting unit operable to convert incident RF energy to direct current (DC); a storage unit operable to store recovered DC power; one or more sensors for sensing; a backscatter communication interface to backscatter energy to communicate one or more packets using a frequency-shift keying (FSK) modulator; and a microcontroller coupled to the energy harvesting and storage units, the one or more sensors, and the backscatter communicator, the microcontroller operable to cause the backscatter communication interface to communicate sensed data from at least one of the one or more sensors while powered by energy previously harvested and stored by the energy harvesting and storage unit.