Scholarlink

<p>Outphasing power amplifiers (PAs) enable high efficiency under output back-off through constant-envelope operation, making them attractive for wireless power transfer (WPT) systems. However, in practical wearable scenarios, overall efficiency is strongly influenced by the interaction between the power combiner and the coupling-dependent impedance of the inductive link—an effect that has not been systematically characterized. In this work, we present a system-level analytical framework that jointly models outphasing PA operation, Wilkinson and Chireix combiner behavior, and coupling-dependent WPT load variations. The proposed approach enables explicit determination of optimal operating conditions as a function of the coupling coefficient. The analysis shows that for the Wilkinson combiner, the optimal outphasing angle is always θ = 0°, with efficiency primarily limited by wireless link coupling. In contrast, for the Chireix combiner, peak efficiency consistently occurs at the compensation angle θc, while its magnitude is strongly modulated by coupling conditions. These results translate into practical design insights: Chireix-based architectures with θc = 60°–70° can outperform Wilkinson combiners by up to 8% points at moderate coupling (k ≈ 0.2), whereas Wilkinson configurations offer greater robustness under weak or dynamically varying coupling (k &lt; 0.15). Circuit-level harmonic balance simulations for both Wilkinson and Chireix combiners further confirm the analytical trends, demonstrating that the predicted efficiency behavior is physically realizable for both topologies. The proposed framework provides actionable guidelines for early-stage design and architecture selection in wearable WPT systems without requiring device-level or full electromagnetic simulations.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Coupling-aware efficiency modeling of outphasing power amplifiers for wearable wireless power transfer

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月3日

查看全文
  • Nizar Brahim,
  • Fawwaz Hazzazi,
  • Giuseppina Monti,
  • Luciano Tarricone,
  • Hichem Taghouti,
  • Abdelkader Mami

摘要

Outphasing power amplifiers (PAs) enable high efficiency under output back-off through constant-envelope operation, making them attractive for wireless power transfer (WPT) systems. However, in practical wearable scenarios, overall efficiency is strongly influenced by the interaction between the power combiner and the coupling-dependent impedance of the inductive link—an effect that has not been systematically characterized. In this work, we present a system-level analytical framework that jointly models outphasing PA operation, Wilkinson and Chireix combiner behavior, and coupling-dependent WPT load variations. The proposed approach enables explicit determination of optimal operating conditions as a function of the coupling coefficient. The analysis shows that for the Wilkinson combiner, the optimal outphasing angle is always θ = 0°, with efficiency primarily limited by wireless link coupling. In contrast, for the Chireix combiner, peak efficiency consistently occurs at the compensation angle θc, while its magnitude is strongly modulated by coupling conditions. These results translate into practical design insights: Chireix-based architectures with θc = 60°–70° can outperform Wilkinson combiners by up to 8% points at moderate coupling (k ≈ 0.2), whereas Wilkinson configurations offer greater robustness under weak or dynamically varying coupling (k < 0.15). Circuit-level harmonic balance simulations for both Wilkinson and Chireix combiners further confirm the analytical trends, demonstrating that the predicted efficiency behavior is physically realizable for both topologies. The proposed framework provides actionable guidelines for early-stage design and architecture selection in wearable WPT systems without requiring device-level or full electromagnetic simulations.