Harvesting or scavenging the RF(Radio Frequency) energy, better known by its engineering name — “RF energy Scavenging”, is one of the emerging fields, with very good research opportunities. It is a technique, by which, we utilize the RF energy present in the external atmosphere, by scavenging, and convert it into an useful electrical output for driving a load, either directly, or, indirectly, by storing the output energy in a battery and later using it to drive that load. This RF energy scavenging technique has been applied by us to the mobile communication devices like mobile phones, laptops, etc. The reason for the choice of this particular class of devices is explained next.