Fast Power Density Assessment of 5G Mobile Handset Using Equivalent
Currents Method
Abstract
As the fifth-generation (5G) mobile communication is utilizing
millimeter-wave (mmWave) frequency bands, electromagnetic field (EMF)
exposure emitted from a 5G mmWave mobile handset should be evaluated and
compliant with the relevant EMF exposure limits in terms of peak
spatial-average incident power density. In this work, a fast power
density (PD) assessment method for a 5G mmWave mobile handset using the
equivalent currents (EQC) method is proposed. The EQC method utilizes
the intermediate-field (IF) data collected by a spherical measurement
system to reconstruct the EQCs over a reconstruction surface, and then
computes the PD in close proximity of the mobile handset with acceptable
accuracy. The performance of the proposed method is evaluated using a
mmWave mobile handset mock-up equipped with four quasi-Yagi antennas.
The assessed PD results are compared with those computed using full-wave
simulations and also those measured with a planar near-field (NF)
scanning system. In addition, three influencing factors related to the
accuracy of the EQC method, namely, the angular resolution, the phase
error, and the handset position in the IF measurements, are also
analyzed. The proposed method is a good candidate for fast PD assessment
of EMF exposure compliance testing in the mmWave frequency range.