An Arbitrary-Frequency Dual-Band High-Efficiency Rectifier Employing a Novel Frequency-Selective Power Allocation Network

This letter presents a novel frequency-selective power allocation network enabling high-efficiency arbitrary dual-band microwave rectification. The proposed design utilizes a frequency-selective network (FSN), composed of two pairs of quarter-wavelength transmission lines, which uniquely achieves power allocation by frequency-dependent impedance transformation, allowing independent optimization of each subrectifier. This approach significantly improves rectification efficiency at both frequencies and extends the optimal input power range. The FSN also reduces impedance variations, further enhancing the rectifier's performance. The proposed design method applies to rectifiers operating at arbitrary dual frequencies. A prototype dual-band rectifier operating at 2.45 and 5.8 GHz is designed, fabricated, and tested. The experimental results demonstrate peak efficiencies of 78.62% and 63.4% at 2.45 and 5.8 GHz, respectively. Moreover, the RF-dc power conversion efficiency exceeds 50% over a wide input power range (–2 to 18.3 dBm at 2.45 GHz and 3–19.7 dBm at 5.8 GHz), corresponding to input power dynamic ranges of 20.3 and 16.7 dB, respectively.