High-Isolated Wireless Power and Information Codelivery by Exploiting Backscattered Second Harmonics

In this letter, a modified hybrid coupler is employed to facilitate high isolation between its fundamental (
ω
₀
) and second harmonic (2
ω
₀
) operational bands at isolation (ISO) port, which establishes dual channels for both power delivery and harmonic backscattering (
ω
₀
: IN→DIR/COU, 2
ω
₀
: IN→ISO). Additionally, the
λ
₀
/8 open and short stubs are implemented in the coupler with an extended bandwidth centered at 2
ω
₀
to avoid frequency offset. Agreements between simulated and measured (74.3%) RF-to-DC power conversion efficiency can be obtained by two subrectifiers from DIR/COU ports with an incident power of 19.5 dBm at the IN port while achieving low insertion loss (0.6 dB at 2
ω
₀
) and high isolation (28 dB at
ω
₀
) from IN to ISO ports. For system validation, a pair of share-apertured dual-band dual-polarized antennas is employed for cross-polarized up (
ω
₀
/2
ω
₀
) and down (2
ω
₀
) links. At the same time, an
on/off
keying modulation is implemented through the second harmonic channel (IN→ISO) for backscattering. According to the experimental results, such a system achieves high-isolated wireless power and information codelivery.