Multicoil Telemetry System for Compensation of Coil Misalignment Effects in Implantable Systems

Inductive coupling-based wireless power transfer (WPT) is commonly used for near-field power and data transfer to implanted electronics. Some implanted coils undergo relative motion during device operation causing variation in magnetic coupling from their normal position. To ensure stable power transfer efficiency and frequency bandwidth, these WPT systems should have high tolerance with coupling variation. In this letter, a multicoil-based WPT system is utilized to achieve high tolerance for system power transfer efficiency and data bandwidth. It is demonstrated that a multicoil WPT system can reduce variation by half in power transfer efficiency (PTE) and by one third in frequency bandwidth compared to a two-coil WPT system with the same dimensions and operating conditions.