A Dual-Band Rectenna with High RF-to-DC Conversion Efficiency for Ambient Wireless Power Harvesting

1) A compact 50 mm × 45 mm dual-band antenna is
presented, with a simulated reflection coefficient below
−23 dB at 2.44 GHz and 4.71 GHz on low-cost FR-4,
and radiation efficiencies of 89% and 78–80% at the two
bands, respectively.
2) A dual-band T-junction matching network is designed
to simultaneously transform the 50 Ω antenna-port
impedance into the complex, frequency- and power-
dependent impedance of a voltage-doubler rectifier.
3) A complete rectenna is designed and verified through
harmonic-balance circuit simulation, achieving peak RF-
to-DC conversion efficiencies of 90% at 2.44 GHz and
88% at 4.71 GHz, on par with or exceeding recently
reported rectenna designs.