Electromagnetic interference in WPT: mitigating losses from metallic backplates

Perfectly designed transmitter (Tx) and receiver (Rx) coils do not guarantee high wireless power transfer (WPT) efficiency. Even with correctly tuned circuits, performance often drops when the coils are assembled into the final product. The root cause is usually nearby metallic and magnetic parts—such as metal backplates, alignment magnets, battery casings, and chassis screws.