A Flexible-Compact Dipole Rectenna for RF Energy Harvesting Around 2.45 GHz

This paper proposes a flexible-compact dipole rectenna for radio frequency (RF) energy harvesting around 2.45 GHz. The overall dimension of the rectenna is 14 mm × 50 mm, which is suitable for some wireless sensors with small sizes. The proposed dipole antenna has an S11 of −33.9 dB at 2.42 GHz and a maximum gain of 2.45 dB. The antenna has been verified to have a resonant frequency shift when bent at radius of 50 cm and 80 cm, but the S11 parameter in the 2.3 GHz to 2.5 GHz band remains below −10 dB. A rectifier is fabricated above the antenna to convert RF energy to DC output. The open-circuit voltage of the rectenna can be up to 0.45 V at a maximum distance of 14.43 m from an RF energy emitter, which is available to power wireless sensors with low profile structures.