A Dual-Band Rectifying Antenna Design for RF Energy Harvesting

A novel dual-band rectifying antenna (also termed rectenna) is designed to harvest ambient energy at WIFI frequencies. The proposed rectenna consists of a Coplanar Waveguide (CPW) Folded-Slot (FS) antenna, a two-stages matching network, a half-wave rectifier circuit, and a resistive load. The CPW FS antenna is designed and demonstrated to resonate at both 2.4 and 5.2 GHz at a compact size of 55mmx30mm with a measured Return Loss (RL) higher than 20dB at each resonance, respectively. Harmonic Balance (HB) simulation is then performed to sweep input power levels and load resistance values to achieve the highest RF-DC conversion efficiency and corresponding output DC voltages. Expected RF-DC conversion efficiency and output DC voltage level at first resonance are 63.38% and 1.4V at an input power of 13 dBm and a load of 150 Omega. At the secondary resonance, the maximum conversion efficiency and output voltage can reach up to 65.4% and 1.53V at input power of 13 dBm and load of 150 Omega.