Cellular it has less self discharge ability and
Posted On June 9, 2019
Cellular telephone technology became commercially available in the 1980’s. When the cellular phone was first implemented, it was enormous in size by today’s standards. This reason is two-fold; the battery had to be large, and the circuits themselves were large. The circuits of that time used in electronic devices were made from off the shelf integrated circuits (IC). These large circuit boards required large amounts of power, which meant bigger batteries. However, as technology has advanced and made our phones smaller and easier to use, we still have one of the original problems: we must plug the phone into the wall in order to recharge the battery. RF energy harvesting is a field whose time has come and its possibilities need to be explored. RF energy is everywhere. We are being bombarded with Radio Frequency energy which is emitted by sources that generate high electromagnetic fields such as TV signals, wireless radio networks and cell phone towers. Even it is new idea, many researches have been done for the optimization of RF energy harvesting system. Many of the works are related with regard to the optimization of antenna, some are with matching network and voltage doubler circuit. The first major obstacle is that it is not a trivial problem to capture energy from the air. We will use a concept called energy harvesting. Energy harvesting is the idea of gathering transmitted energy and either using it to power a circuit or storing it for later use. The concept needs an efficient antenna which collects ambient RF power and transmits it to the rectifier; therefore it must be designed to capture as much energy as possible along with a charge pump technology because it does two work , first it rectifies RF-DC and secondly it amplifies the voltage according to the stages of doubler circuit. Impedance matching is needed to provide maximum power transfer between the source or RF energy and its load. This is especially important if you deal with low amplitude signals. The converted DC voltage will be stored in a storage unit , super capacitors will be used as it has less self discharge ability and low internal impedance and that stored DC voltage will be used to power up any small wearable device.