Wireless@kth are pleased to forward the invitation to the following PhD dissertation at the School of Electrical Engineering and Systems at KTH.
Please also note the time and place, not the same as usual!
Full Invitation details here
In the thesis, the user body effect on antennas in a mobile terminal is discussed. In order to overcome the degradation of Multiple-Input Multiple-Output (MIMO) performance due to the user body effect, a quad-elements MIMO antenna array which can mitigate the body effect through an adaptive antenna switching method is introduced for 4G mobile terminals. In addition, various bezel MIMO antennas that are robust to the impedance mismatching caused by the user effect have also been presented.
The study of user body effect is later extended to frequency bands at 15 GHz and 28 GHz for future 5G communication systems. The results reveal that a human body will cause a significant shadowing loss, which will be a critical loss in 5G cellular networks.
The electromagnetic field (EMF) exposure of a mobile terminal is also studied in this thesis. Below 6 GHz, the simultaneous transmission specific absorption rate (SAR) for MIMO antennas is the primary concern due to its complicated assessment procedures. Above 6 GHz, the free space power density is adopted as the basic parameter of exposure limits globally, and preliminary studies have been presented to address major challenges in EMF exposure assessment for 5G mobile terminals.
Kun Zhao, PhD student, Electromagnetic Engineering