In Situ Measurement of UHF Wearable Antenna Radiation Efficiency Using a Reverberation Chamber

The radiation efficiency and resonance frequency of five compact antennas worn by nine individual test subjects was measured at 2.45 GHz in a reverberation chamber. The results show that, despite significant differences in body mass, wearable antenna radiation efficiency had a standard deviation less than 0.6 dB and the resonance frequency shift was less than 1% between test subjects. Variability in the radiation efficiency and resonance frequency shift between antennas was largely dependant on body tissue coupling which is related to both antenna geometry and radiation characteristics. The reverberation chamber measurements were validated using a synthetic tissue phantom and compared with results obtained in a spherical near field chamber and finite-difference time-domain (FDTD) simulation.

[1]  William Scanlon,et al.  Low-Profile Patch Antennas for Over-Body-Surface Communication at 2.45 GHz , 2007 .

[2]  John C. Batchelor,et al.  Covert dual-band wearable button antenna , 2006 .

[3]  David Linton,et al.  Low-Profile Microstrip Patch Antenna for Over-Body Surface Communication at 2.45 GHz , 2007, 2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring.

[4]  M. Stuchly,et al.  A study of the handset antenna and human body interaction , 1996 .

[5]  G. Troster,et al.  Design and Characterization of Purely Textile Patch Antennas , 2006, IEEE Transactions on Advanced Packaging.

[6]  Kin-Lu Wong,et al.  Characteristics of a 2.4‐GHz compact shorted patch antenna in close proximity to a lossy medium , 2005 .

[7]  Per-Simon Kildal,et al.  Correlation and capacity of MIMO systems and mutual coupling, radiation efficiency, and diversity gain of their antennas: simulations and measurements in a reverberation chamber , 2004, IEEE Communications Magazine.

[8]  William Scanlon,et al.  Numerical analysis of bodyworn UHF antenna systems , 2001 .

[9]  W. Scanlon,et al.  Antennas for Over-Body-Surface Communication at 2.45 GHz , 2009, IEEE Transactions on Antennas and Propagation.

[10]  C. Parini,et al.  Antennas and propagation for on-body communication systems , 2007, IEEE Antennas and Propagation Magazine.

[11]  C. Orlenius,et al.  Calculated and measured absorption cross sections of lossy objects in reverberation chamber , 2004, IEEE Transactions on Electromagnetic Compatibility.

[12]  P.-S. Kildal,et al.  Designing reverberation chambers for measurements of small antennas and wireless terminals: Accuracy, frequency resolution, lowest frequency of operation, loading and shielding of chamber , 2006, 2006 First European Conference on Antennas and Propagation.