A 6.78 MHz and 90% Efficiency Resonant Wireless Power Supply Technique With the Dual Voltage/Current Tuning Inductance to Supply 30 cm Short-Distance Base Stations for 5G Communications

• Published in: IEEE transactions on power electronics 2021-10, Vol.36 (10), p.11774-11784
• Main Authors: Chen, Hsuan-Yu, Chung, Kai-Cheng, Huang, Jia-Rui, Chen, Shao-Qi, Chen, Ke-Horng, Lin, Ying-Hsi, Lin, Shian-Ru, Tsai, Tsung-Yen
• Format: Article
• Language: English
• Subjects: Capacitors; Class-E power amplifier (PA); dual voltage/current (V/C) inductance controller; Efficiency; Gallium nitride; gallium nitride (GaN); Inductance; inductance tuning technique; Inductors; phase difference (PD) tracking technique; Phase locked loops; Switches; Tracking; Tuning; Wall thickness; wireless power supply (WPS); Zero voltage switching; zero voltage switching (ZVS)
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2021.3069279

This article proposes a dual voltage/current ( V/C ) inductance controller, which has good impedance tracking capability without any high-voltage stress problems. Besides, the proposed dual-mode phase-locked loop (D-PLL) technique can detect the phase difference between voltage and current of the antenna by fast tracking PLL and the accuracy-improved PLL for inductive and capacitive loads, thereby improving efficiency. Therefore, the 5G small base station on the receiver side (RX) can receive 27.8 W of power with 50% efficiency when the wall thickness to the transmitter side (TX) is 25.2 cm. In the case where the distance between TX and RX is close to zero, 50 W higher power with 90% efficiency can be achieved. Accordingly, the efficiency of resistive and inductive loads can be increased by 13% and 41%, respectively.