In this paper, different measurement schemes are studied in order to investigate the possibilities and limitations of scalar- and vector-based measurement systems for radio frequency electromagnetic fields compliance assessments of fifth generation mobile communication user equipment (UE). Two UE antenna array designs, transmitting at 15 GHz and employing patch and notch antenna elements, are considered for different phase excitations. Using free space power density as the exposure metric, the maximum permissible transmitted power of UE, compliant with the maximum permissible exposure limits specified by the U.S. Federal Communications Commission (FCC) and the basic restrictions of the International Commission on Non-Ionizing Radiation Protection, is determined. The accuracy of different measurement schemes is assessed using numerical simulation. Verifying measurements is carried out in a semianechoic chamber. The results indicate that, for UE employing array antennas and intended to be used in immediate vicinity of the human body, scalar measurement systems used in combination with straightforward field combination techniques will lead to overly conservative results. A more accurate and less conservative approach for these products is to conduct separate measurements for different excitations in order to span the space of possible excitations. This will result in a more complicated measurement setup and increase the measurement time, which points to a need for very fast measurement systems.
|Journal||IEEE Transactions on Antennas and Propagation|
|Number of pages||12|
|Publication status||Published - Dec 2017|
Bibliographical noteFunding Information:
Manuscript received November 2, 2016; revised April 21, 2017; accepted May 29, 2017. Date of publication June 7, 2017; date of current version November 30, 2017. This work was supported in part by Swedish VR, in part by AOARD, in part by the Fundamental Research Funds for Central Universities, in part by the Program of Zhejiang Leading Team of Science and Technology Innovation under Grant 2010R50007, and in part by the China Scholarship Council under Grant 201506320137. (Corresponding author: Sailing He.) B. Xu and S. He are with the Department of Electromagnetic Engineering, School of Electrical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden, and also with the Zhejiang Provincial Key Laboratory for Sensing Technologies, Centre for Optical and Electromagnetic Research, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310058, China (e-mail: email@example.com).
© 2017 IEEE.
- Antenna array
- assessment method
- fifth generation (5G) mobile communication systems
- maximum permissible transmitted power (MPTP)
- power density
- radio frequency (RF) electromagnetic field (EMF) exposure
- user equipment (UE)