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 (ω0) and second harmonic (2ω0) operational bands at isolation (ISO) port, which establishes dual channels for both power delivery and harmonic backscattering (ω0: IN→DIR/COU, 2ω0: IN→ISO). Additionally, the λ0/8 open and short stubs are implemented in the coupler with an extended bandwidth centered at 2ω0 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 2ω0) and high isolation (28 dB at ω0) from IN to ISO ports. For system validation, a pair of share-Apertured dual-band dual-polarized antennas is employed for cross-polarized up (ω0/2ω0) and down (2ω0) 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.