TLM design of a compact PIFA rectenna

Interest for Radio Frequency energy harvesting systems is increasing since they allow to remotely powered devices involving low power consumption, located in unreachable area or needing expensive maintenance costs. Miniaturization is also of great interest when such device needs to be embedded into mobile systems. In this paper, a compact PIFA rectenna (rectifier + antenna) was designed and evaluated for the Radio Frequency energy harvesting systems at 2.45GHz. By using a full-wave time domain technique (TLM), a global simulation is presented for designing a complete rectenna based on a RF-to-DC converter coupled to a miniature PIFA antenna. The RF-to-DC conversion efficiency of 60% is achievable over the input power range of 5-30mW. Also, a 1.9V output DC voltage could be reached when the RF power density is 1.6mW/cm².