Small Multi-Band Antenna with Tuning Function for Body-Centric Wireless Communications

Chia-Hsien LIN  Zhengyi LI  Kazuyuki SAITO  Masaharu TAKAHASHI  Koichi ITO  

Publication
IEICE TRANSACTIONS on Communications   Vol.E95-B   No.10   pp.3074-3080
Publication Date: 2012/10/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E95.B.3074
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Medical Information Communication Technology for Disaster Recovery and Human Health Care Support)
Category: 
Keyword: 
body-centric wireless communications (BCWCs),  planar inverted-F antenna (PIFA),  industrial-scientific-medical (ISM),  WiMAX,  

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Summary: 
The research on body-centric wireless communications (BCWCs) is becoming very hot because of numerous applications, especially the application of E-health systems. Therefore, a small multi-band and low-profile planar inverted-F antenna (PIFA) with tuning function is presented for BCWCs in this paper. In order to achieve multi-band operation, there are two branches in the antenna: the longer branch low frequency band (950–956 MHz), and the shorter branch with a varactor diode embedded for high frequency bands. By supplying different DC voltages, the capacitance of the varactor diode varies, so the resonant frequency can be tuned without changing the dimension of the antenna. While the bias is set at 6 V and 14 V, WiMAX and ISM bands can be covered, respectively. From the radiation patterns, at 950 MHz, the proposed antenna is suitable for on-body communications, and in WiMAX and ISM bands, they are suitable for both on-body and off-body communications.