Journal
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
Volume 68, Issue 7, Pages 5733-5743Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/TIE.2020.3000102
Keywords
Coils; Couplings; Transmitters; Receivers; Integrated circuit modeling; Magnetic resonance; Closed loop; injection locking; magnetic resonant coupling; maximum efficiency tracking; power oscillator; positive feedback; resonance frequency tracking; wireless power transfer (WPT)
Categories
Funding
- Ministry of Education, Singapore [AcRF TIER 1-2018T1-001-120 (RG 86/18)]
- Nanyang Technological University [M4082082.040]
Ask authors/readers for more resources
This article presents a closed-loop transmitter with automatic resonance frequency tracking to maintain high power transfer efficiency in the over-coupled region. The prototype, implemented in specific technology, maintains good power amplifier efficiency even at a highly over-coupled spacing of 10 mm.
This article presents a closed-loop transmitter for wireless power transfer with automatic resonance frequency tracking to maintain high power transfer efficiency in the over-coupled region. The transmitter consists of a source oscillator, power amplifier (PA), PA driver, matching network, and feedback circuitry. By injecting the resonant output of coupled antenna coils into a source oscillator to form a positive feedback loop, the source oscillator is injection-locked and the closed-loop transmitter functions as a power oscillator with the oscillation frequency determined by the resonance of the coupled coils. The proposed resonant frequency tracking minimizes the change in the input impedance presented to the PA, and hence mitigates mismatch that causes a sharp drop in the PA efficiency of conventional transmitters. Implemented in 0.13 mu m Bipolar-CMOS-DMOS (BCD) technology, the prototype maintains PA efficiency above 60% even at highly over-coupled spacings (10 mm), which is significantly below the critical coupling spacing (40 mm). Compared to a transmitter without feedback (i.e., running in open loop), the transfer efficiency at a coupling distance of 10 mm is improved by 6.6 times and the charging range with power transfer efficiency over 50% is also doubled.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available