Comparative Analysis and Development Strategies for Far-Field Wireless Charging Technologies

Abstract

Since its inception, wireless charging technology has embodied humanity's aspiration to break free from cable constraints and achieve a seamless energy supply. However, mainstream standards like the electromagnetic induction-based Qi standard face critical limitations: their effective charging range typically spans merely a few millimeters to centimeters, requiring strict alignment between transmitter and receiver. This "near-field" charging mode essentially requires physical proximity, falling short of the ideal of truly seamless charging enabled simply by entering a room. To overcome these spatial constraints, research has shifted towards far-field wireless power transfer (WPT), which enables energy delivery over distances ranging from centimeters to meters. This paper goes beyond a simple overview; it provides a systematic comparative analysis of the principal far-field methods, namely magnetic resonance coupling and directional electromagnetic radiation. It meticulously examines their respective operational principles, advantages, disadvantages, and suitability for different application scenarios. Building on this analysis, the paper discusses potential development strategies and system-level optimization approaches. The findings aim to offer a scientific basis and technical guidance for the future advancement and practical deployment of this transformative technology.