Work

Efficient wireless power transfer enabled by anti-PT-symmetric nonlinear feedback

Year: 2025

Type: article

Abstract: Efficiency and robustness are the fundamental challenges in resonance wireless power transfer (WPT). The application of non-Hermitian physics, particularly parity-time (PT) symmetry, in the field of WPT is currently under intense scrutiny from both theoretical and experimental perspectives. Typically, constructing an N ᵗʰ-order non-Hermitian system requires N coupled resonant coils. Here, we introduce a synthetic dimension via a bypass capacitor in a basic inductor-capacitor circuit, enabling arbitrary-order non-Hermitian WPT using only one resonant coil. As a demonstration, we realize a 3 rd -order anti-PT-symmetric system based on a dual-resonance WPT structure. By incorporating nonlinear saturation gain in the transmitter coil, we achieve nonlinear-feedback-enhanced WPT with adaptive robustness, eliminating the need for active frequency modulation. This approach circumvents the complexity of multiple gain elements and extends the applicability of anti-PT symmetry to long-distance power transfer. Our work represents an alternative pathway to high-performance wave-functional devices. • Single-coil high-order non-Hermitian wireless power transfer • Nonlinear feedback enables adaptive frequency locking • Anti-PT symmetry extends robust power transfer range • Synthetic dimension reduces system size and loss Wireless power transfer (WPT) has the potential to revolutionize applications from medical implants to electric vehicles. However, it faces two major challenges: efficiency tends to drop sharply with distance and systems require continuous tuning to maintain performance. Recent advances leveraging non-Hermitian physics—particularly parity-time (PT) symmetry—have offered new solutions, but higher-order systems typically need multiple resonant coils, increasing complexity and energy loss. This work addresses these limitations by adopting anti-PT symmetry and introducing a “meta-coil” design. By adding a bypass capacitor to create a synthetic dimension within a simple LC circuit, a single coil can emulate higher-order resonant systems. Integrating a nonlinear saturation gain module enables adaptive power transfer, maintaining high efficiency over varying distances without active frequency tuning. Experimental results demonstrate transfer efficiency exceeding 75% across a broad range of distances, significantly outperforming conventional linear systems. This approach eliminates the need for multiple gain elements and extends anti-PT-symmetry concepts to long-range WPT. Our work not only offers a new paradigm for studying non-Hermitian physics via synthetic dimensions but also paves the way for applications in wireless sensing and communication. Wireless power transfer faces efficiency and tuning challenges over distance, and higher-order systems often require multiple coils, increasing complexity and energy loss. Wang et al. demonstrate a synthetic-dimension-based meta-coil that realizes high-order anti-PT symmetry for wireless power transfer. Incorporating nonlinear saturation gain enables adaptive frequency locking and robust efficiency across varying distances without active tuning, offering a compact and efficient solution for next-generation wireless energy systems.

Source: Newton

DOI: 10.1016/j.newton.2025.100267