Design of compact integrated diodes Pifa rectennas for energy harvesting application

In this paper we propose new compact PIFA rectennas dedicated to the powering of small wireless sensors of low power. The compactness is achieved by removing the filtering and impedance matching circuits and by integrating directly inside the PIFA several Schottky diodes. The optimization of such high integrated and nonlinear radiating structure can be performed only by the mean of a global time domain simulation technique. A Homemade software based on TLM method was then used to design 40×40mm ² PIFA rectennas integrating up to four SMS7630 Schottky diodes. They are capable of harvesting up to 3.67mW DC power in a 3.5kfi load resistor from a plane wave with an extremely low power density of 1μW/cm ² and with a frequency of 2.45GHz.