Applying the human body as a transmitting antenna by coupling large RF power might
not be ethical and also the power dissipated inside the human body might exceed the
recommended limit. But, the human body can be used as a receiving monopole antenna
for applications that involve low power electromagnetic fields or fields that are present
in the environment. One such application is the use of the human body as a receiving
antenna for RF energy harvesting. Currently, the interest in the area of RF energy
harvesting is growing particularity in the field of self-sustained and autonomous sensor
networks. Research focused on the ambient RF energy in the digital TV band because
there is uninterrupted available broadcast power and also the antenna size required is
relatively small. Several ambient RF energy surveys showed that the available power
in the FM band is comparable or sometimes better than the available power in digital
TV bands [85], [86], [87]. But the idea of designing an RF energy harvesting system in
FM band has been abandoned for the primary reason that a larger antenna is required
at this frequency band. By designing an optimal matching network, the human body
might be used as antenna for RF energy harvesting in the FM band to power wearable
or implanted antennas.