Wireless Power Transmission Circuits for Portable Devices

Abstract

For wireless power transmission of mobile and wearable medical devices, this dissertation presents wireless power receiver, wireless power transceiver, and wireless power charger. In wireless power receiver for mobile devices, the reverse leakage current of the active rectifier is prevented by a delay locked loop (DLL) based delay compensation circuit. The buck converter of the wireless power receiver operates in the discontinuous-conduction mode at the light load and its switching frequency is automatically selected according to the amount of the load current to improve the power efficiency. Also, the bi-directional DC-DC converter has been developed for a wireless power transceiver which enables a mobile device to receive and transmit power wirelessly. With the bi-directional DC-DC converter, the form-factor of the proposed wireless power transceiver can be reduced. And the wireless power charger has been implemented to charge the battery of the wearable medical device. The status of the battery can be transmitted to the transmitter by the in-band communication circuit.|이 논문은 모바일 및 착용 가능한 의료 기기의 무선 전력 전송을 위한 무선 충전 수신기, 무선 충전 송수신기, 무선 충전기를 각각 설명하고 있다. 지연 고정 루프를 기반으로 한 보상 회로를 이용하여 모바일 기기를 위한 무선 충전 수신기의 능동형 정류기의 역방향 누설 전류를 방지하였다. 무선 충전 수신기의 강압 컨버터는 작은 출력 전류 상황에서 비연속 도통 모드로 동작하며 효율을 향상시키기 위하여 스위칭 주파수가 출력 전류에 따라 미리 정해진 주파수 중의 하나로 선택된다. 또한, 모바일 기기가 무선으로 전력을 받을 수 있을 뿐 아니라 전달 해 줄 수 있는 무선 충전 송수신기를 위한 양방향으로 동작하는 직류-직류 전압 변환기를 개발하였다. 제안된 양방향으로 동작하는 직류-직류 전압 변환기를 적용하여 무선 전력 송수신기의 form-factor를 줄였다. 그리고 착용 가능한 의료기기의 배터리를 충전하기 위한 무선 전력 충전기를 개발하였다. 배터리의 상태는 in-band 통신 회로에 의해 송신기로 전달 된다.; For wireless power transmission of mobile and wearable medical devices, this dissertation presents wireless power receiver, wireless power transceiver, and wireless power charger. In wireless power receiver for mobile devices, the reverse leakage current of the active rectifier is prevented by a delay locked loop (DLL) based delay compensation circuit. The buck converter of the wireless power receiver operates in the discontinuous-conduction mode at the light load and its switching frequency is automatically selected according to the amount of the load current to improve the power efficiency. Also, the bi-directional DC-DC converter has been developed for a wireless power transceiver which enables a mobile device to receive and transmit power wirelessly. With the bi-directional DC-DC converter, the form-factor of the proposed wireless power transceiver can be reduced. And the wireless power charger has been implemented to charge the battery of the wearable medical device. The status of the battery can be transmitted to the transmitter by the in-band communication circuit.