Coherently assisted wireless power transfer through poorly transparent barriers

Abstract Reflective walls and shields often block wireless power transfer unless the barrier is modified to create a narrow transmission window. Here we propose an alternative that leaves the barrier unchanged: a phase-locked auxiliary emitter on the receiver side launches a second wave whose amplitude and phase are set from the measured complex scattering parameters of the barrier. Using a simple two-port scattering model, we derive closed-form conditions to cancel the reflection seen by the transmitter and to maximize the net power extracted on the receiver side. In the ideal lossless limit, the method can eliminate back-reflection and deliver all transmitter power to the receiver side even when one-sided transmission is nearly zero. Analytical and full-wave examples (a high-index Fabry–Pérot slab and a perforated metallic screen) confirm near-unity effective transmission and large enhancements without altering the obstacle. For lossy barriers, the same formulas provide the optimal auxiliary waveform and show when positive net delivery remains possible. The effect relies on interference between two coherent drives and therefore requires phase synchronization; it is not a passive ‘transparency’ of the barrier.