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.