This paper studies the fundamental trade-off between power transfer efficiency (PTE) and spectral efficiency for simultaneous power and data transfer through near-field inductive links. A mathematical analysis is used to establish the relationship between PTE and channel capacity as a function of link parameters such as coupling coefficient (k), load resistance, and surrounding environment. The analysis predicts that the optimum trade-off between power and data transfer is particularly dependent on k, which is a monotonically-decreasing function of axial distance (d) between the coils. Real-time adaptation of the link parameters (such as load resistance and modulation type) is proposed to allow the power-data trade-off to be optimized over a wide range of distances and coupling coefficients. A benchtop prototype of such an adaptive link is demonstrated at a center frequency of 13.56 MHz. The prototype uses an ultrasound transducer to measure d with accuracy < 0.1 mm, and uses this information to autonomously optimize both data rate (up to ~50 Mbps) and PTE (up to ~25%) as the coil-coil distance varies within the 4-15 mm range.

中文翻译：

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用于生物医学植入物的自优化感应功率/数据链路。

本文研究了功率传输效率（PTE）与频谱效率之间的基本权衡，以通过近场感应链路同时进行功率和数据传输。使用数学分析来建立PTE和信道容量之间的关系，该关系是链接参数（例如，耦合系数（k），负载电阻和周围环境）的函数。分析预测，功率与数据传输之间的最佳折衷尤其取决于k，k是线圈之间轴向距离（d）的单调递减函数。建议对链路参数（例如负载电阻和调制类型）进行实时调整，以使功率数据的权衡能够在较宽的距离和耦合系数范围内得到优化。在中心频率为13.56 MHz的情况下演示了这种自适应链路的台式原型。原型使用超声换能器测量d，精度<0.1 mm，并且随着线圈线圈距离的变化，该信息可自动优化数据速率（最高〜50 Mbps）和PTE（最高〜25％）。 4-15毫米范围。