AI 中文总结
研究在实际激励约束下虚拟临界耦合（VCC）的储能能力，利用时间耦合模理论推导解析表达式，分析理想无损谐振器和有损微波腔，表明VCC主要是提高能量传输效率和控制瞬态激励的方法，非增加绝对储能的机制。
AI 中文摘要
虚拟临界耦合（VCC）已成为一种通过定制入射波形实现谐振系统无反射激励的有前景的方法。然而，通常在不考虑激励源实际约束的情况下评估常归因于VCC的储能增强。本文在实际最大幅度约束下重新审视VCC的储能能力。利用时间耦合模理论，推导了连续波（CW）、理想VCC（IVCC）和受约束VCC（CVCC）激励的储能解析表达式。结果表明，当固定最大激励幅度时，CVCC激励在整个激励持续时间内储能比CW激励少，同时保持VCC实现的高能量传输效率和无反射激励。这些解析表达式用于分析理想无损谐振器和先前用于VCC等离子体点火的实验有损微波腔。结果表明，在实际源限制下，VCC应主要被视为提高能量传输效率和控制瞬态激励的方法，而不是增加绝对储能的内在机制。
英文摘要
Virtual critical coupling (VCC) has emerged as a promising approach for achieving reflectionless excitation of resonant systems through tailored incident waveforms. However, the energy storage enhancement often attributed to VCC is generally assessed without considering practical constraints imposed by the excitation source. In this work, we revisit the energy storage capabilities of VCC under a realistic maximum-amplitude constraint. Using temporal coupled-mode theory, we derive analytical expressions for the stored energy of continuous wave (CW), ideal VCC (IVCC), and constrained VCC (CVCC) excitations. While the conventional IVCC excitation leads to higher stored energy than CW excitation due to its exponentially increasing incident amplitude, we show that this enhancement originates from the larger incident energy delivered by the unconstrained waveform. When the maximum excitation amplitude is fixed, the proposed CVCC excitation stores less energy than CW excitation throughout the excitation duration, while preserving the high energy transfer efficiency and reflectionless excitation enabled by VCC. The analytical expressions are used to analyze both an ideal lossless resonator and an experimentally lossy microwave cavity previously used for plasma ignition by VCC. The results clarify that VCC should primarily be regarded as a method for improving energy transfer efficiency and controlling transient excitation, rather than as an intrinsic mechanism for increasing the absolute stored energy under realistic source limitations.
