A Dual-Band Antenna for RF Energy Harvesting Systems in Wireless Sensor Networks

Table 1

Characteristics of various energy sources and harvested power.

Source	Source power	Harvested power
Ambient light
Indoor	0.1 mW/cm^2	10 μW/cm^2
Outdoor	100 mW/cm^2	10 mW/cm^2
Vibration
Human	0.5 m @ 1 Hz 1 m/s^2 @ 50 Hz	4 μW/cm^2
Industrial	1 m @ 5 Hz 10 m/s^2 @ 1 kHz	100 μW/cm^2
Thermal energy
Human	20 mW/cm^2	30 μW/cm^2
Industrial	100 mW/cm^2	1–10 mW/cm^2
RF
Cell phone	0.3 μW/cm^2	0.1 μW/cm^2