Wideband Harmonic Backscattering Rectifier for Energy-Efficient Localization in Wireless Power Transfer Systems

This study proposes a wideband harmonic backscattering rectifier (HBR) for accurate localization of a device using a second harmonic signal. To backscatter the second harmonic signal with efficient rectification, the proposed transmission-line-based impedance control network (TICN) functions as a dc pass and fundamental frequency stop filter and classifies the dc and second harmonic signals generated from the diode. The TICN with a second harmonic matching network moved the input impedance observed in the dc load to
$0~\Omega $
at
$f_{0}$
and matched it to the second harmonic load at
$2f_{0}$
. The proposed HBR was fabricated with dimensions of 33
$\times $
30 mm. The measured power conversion efficiency (PCE) was maintained over 50% within 2.3–2.9 GHz at 27.3 dBm of input power. A peak conversion gain (CG) of over −12 dB is measured within the wide frequency range. An antenna beam alignment experiment was performed to verify the feasibility of the HBR.