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Application of the planar‐scanning technique to the near‐field dosimetry of millimeter‐wave radiators
Author(s) -
Zhao Jianxun,
Lu Hongmin,
Deng Jun
Publication year - 2015
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/bem.21889
Subject(s) - optics , planar , aperture (computer memory) , wavelength , near and far field , extremely high frequency , plane wave , imaging phantom , millimeter , physics , materials science , acoustics , computer graphics (images) , computer science
The planar‐scanning technique was applied to the experimental measurement of the electric field and power flux density (PFD) in the exposure area close to the millimeter‐wave (MMW) radiator. In the near‐field region, the field and PFD were calculated from the plane‐wave spectrum of the field sampled on a scan plane far from the radiator. The measurement resolution was improved by reducing the spatial interval between the field samples to a fraction of half the wavelength and implementing multiple iterations of the fast Fourier transform. With the reference to the results from the numerical calculation, an experimental evaluation of the planar‐scanning measurement was made for a 50 GHz radiator. Placing the probe 1 to 3 wavelengths from the aperture of the radiator, the direct measurement gave the near‐field data with significant differences from the numerical results. The planar‐scanning measurement placed the probe 9 wavelengths away from the aperture and effectively reduced the maximum and averaged differences in the near‐field data by 70.6% and 65.5%, respectively. Applied to the dosimetry of an open‐ended waveguide and a choke ring antenna for 60 GHz exposure, the technique proved useful to the measurement of the PFD in the near‐field exposure area of MMW radiators. Bioelectromagnetics. 36:108–117, 2015. © 2015 Wiley Periodicals, Inc.