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

• Published in: IEEE antennas and wireless propagation letters Vol. 7; pp. 271 - 274
• Main Authors: Conway, G.A., Scanlon, W.G., Orlenius, C., Walker, C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Bodyworn antennas; efficiency; Finite difference methods; Frequency measurement; Geometry; Imaging phantoms; on-body communications; Resonance; Resonant frequency; Reverberation chamber; Testing; Time domain analysis; wearable antenna radiation; wearable antenna radiation efficiency; wearable antenna radiation efficiency; Bodyworn antennas; on-body communications
• ISSN: 1536-1225; 1548-5757; 1548-5757
• DOI: 10.1109/LAWP.2008.920753

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.