~Tal Pezzuco ~ Senior Capstone Project~

My name is Tal Pezzuco and I am a senior studying electrical engineering at Union College. This webpage is to document my work throughout my capstone project. I would like to thank my advisor Professor James Hedrick for all the help along the way!

~About My Project~

Radio frequency (RF) energy harvesting is when collected electromagnetic energy is turned in a continuous voltage. The use of energy harvesting to power low powered sensors would eliminate the need for electrical wiring as well as be energy efficient. Although this seems great, RF harvesting is extremely difficult at long distances because it is limited to how much ambient energy is in the surrounding atmosphere. But using wireless power transmission can help assist energy harvesting by providing an additional source of power. With the ability to harvest enough RF energy to power a motion sensor, I would be able to build a system that can track how many times a tennis player hits a ball over a net in a rally. If a player can simultaneously keep track of how consistent they are in a point while performing at their best, they would be able to record and improve their tennis ability

~My Design Idea~

To create a system that can sucessfully power a PIR motion sensor using RF harvested energy, I would like to have a transmitter that uses a VHF FM transceiver that is powered at 5V. On the receiving end of the system, there will be a matching circuit consisting of one 68 ohm resistor. The matching circuit will be connected to a doubler consisting of two 1N21C diodes in parallel with two 1nF capacitors. Next, there will be a storage unit that has a 1F super capacitor. The transmitter and receiving circuit will use a half-wave length antenna to communicate. The antenna should be 3.2 feet on both the transmitting and receiving side. A block diagram of the design is shown below.

Design Block Diagram

The PIR sensor needs a minimum of 3 volts input to be powered. So hopefully the design can produce that much voltage. I would also like the transmitter and receiver to be at least 3 feet apart to be a reasonable distance from the tennis net while people are play, for safety reasons.