TY - JOUR
T1 - Compact, Highly Efficient, and Fully Flexible Circularly Polarized Antenna Enabled by Silver Nanowires for Wireless Body-Area Networks
AU - Jiang, Zhi Hao
AU - Cui, Zheng
AU - Yue, Taiwei
AU - Zhu, Yong
AU - Werner, Douglas H.
N1 - Publisher Copyright:
© 2007-2012 IEEE.
PY - 2017/8
Y1 - 2017/8
N2 - A compact and flexible circularly polarized (CP) wearable antenna is introduced for wireless body-area network systems at the 2.4 GHz industrial, scientific, and medical (ISM) band, which is implemented by employing a low-loss composite of polydimethylsiloxane (PDMS) and silver nanowires (AgNWs). The circularly polarized radiation is enabled by placing a planar linearly polarized loop monopole above a finite anisotropic artificial ground plane. By truncating the anisotropic artificial ground plane to contain only 2 by 2 unit cells, an integrated antenna with a compact form factor of 0.41λ0 × 0.41λ0 × 0.045λ0 is obtained, all while possessing an improved angular coverage of CP radiation. A flexible prototype was fabricated and characterized, experimentally achieving S11 <-15 dB, an axial ratio of less than 3 dB, a gain of around 5.2 dBi, and a wide CP angular coverage in the targeted ISM band. Furthermore, this antenna is compared to a conventional CP patch antenna of the same physical size, which is also comprised of the same PDMS and AgNW composite. The results of this comparison reveal that the proposed antenna has much more stable performance under bending and human body loading, as well as a lower specific absorption rate. In all, the demonstrated wearable antenna offers a compact, flexible, and robust solution which makes it a strong candidate for future integration into body-area networks that require efficient off-body communications.
AB - A compact and flexible circularly polarized (CP) wearable antenna is introduced for wireless body-area network systems at the 2.4 GHz industrial, scientific, and medical (ISM) band, which is implemented by employing a low-loss composite of polydimethylsiloxane (PDMS) and silver nanowires (AgNWs). The circularly polarized radiation is enabled by placing a planar linearly polarized loop monopole above a finite anisotropic artificial ground plane. By truncating the anisotropic artificial ground plane to contain only 2 by 2 unit cells, an integrated antenna with a compact form factor of 0.41λ0 × 0.41λ0 × 0.045λ0 is obtained, all while possessing an improved angular coverage of CP radiation. A flexible prototype was fabricated and characterized, experimentally achieving S11 <-15 dB, an axial ratio of less than 3 dB, a gain of around 5.2 dBi, and a wide CP angular coverage in the targeted ISM band. Furthermore, this antenna is compared to a conventional CP patch antenna of the same physical size, which is also comprised of the same PDMS and AgNW composite. The results of this comparison reveal that the proposed antenna has much more stable performance under bending and human body loading, as well as a lower specific absorption rate. In all, the demonstrated wearable antenna offers a compact, flexible, and robust solution which makes it a strong candidate for future integration into body-area networks that require efficient off-body communications.
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U2 - 10.1109/TBCAS.2017.2671841
DO - 10.1109/TBCAS.2017.2671841
M3 - Article
C2 - 28541907
AN - SCOPUS:85019904652
SN - 1932-4545
VL - 11
SP - 920
EP - 932
JO - IEEE transactions on biomedical circuits and systems
JF - IEEE transactions on biomedical circuits and systems
IS - 4
M1 - 7932871
ER -