Analytical computation of distributed capacitance for NFC coil antenna

IEICE Electronics Express

Qun Wang¹  Waheed Q. Khan¹  Xin Jin¹  Zhang H. Tang¹  Xiao M. Yao¹ 

[1] Institute of Materials Science and Engineering, Beijing University of Technology

关键词: capacitance network;    conformal mapping;    distributed capacitance;    NFC;   

DOI  :  10.1587/elex.14.20161147

学科分类：电子、光学、磁材料

来源: Denshi Jouhou Tsuushin Gakkai

【 摘 要 】

A new method for formulating the equivalent distributed capacitance of NFC coil antenna is proposed. This method is based on an analytical approach by conformal mapping for quantifying the capacitance per unit length and then applied the capacitance network method for calculating the equivalent distributed capacitance. The results of this method are verified with simulated and measured results of two different types of antenna and the agreement is >91%. It is also tested that the capacitance between non-adjacent turns cannot be ignored in the equivalent distributed capacitance computation. Furthermore, the effects of the coil width and gap between the two adjacent coils are predicted in calculating the equivalent distributed capacitance for a specific coil antenna. The proposed method will be useful for designing NFC coil antennas with a better accuracy of capacitance.

【 授权许可】

CC BY