RF Energy Harvesting Problem

Hi there! I am a Telecommunication engineer and I have made a energy haravesting circuit for my 4th year project. The problem which i have is that the circuit is not capable of harvesting the RF energy, how can i design an antenna or anything alse which can automatically recieve that energy and drives it to the next stage of the circuit.

The other sections of the circuit are working fine but the reciever section is not working. please help me out in this Problem.