Public defence in Radio Science and Technology, M.Sc. Bing Xue

The title of the thesis: Modeling and Measurements of Human Body Effects on Millimeter-Wave and Sub-Terahertz Handset Antenna Radiation: From Permittivity Estimation to Spherical Coverage

Thesis defender: Bing Xue
Opponent: Dr. Risto Valkonen, Nokia Bell Labs, Finland 
Custos: Prof. Katsuyuki Haneda, Aalto University School of Electrical Engineering

With the increasing demand for high-speed wireless communication, millimeter-wave (mmW) and sub-terahertz (sub-THz) frequencies have become critical for 5G and beyond. However, signal propagation at these frequencies is highly susceptible to free-space path loss and user-induced blockages, such as hand and body effects on handset antennas. Accurately modeling these interactions is essential for improving wireless system performance. 

This thesis addresses the challenges of human body blockages in mmW and sub-THz wireless channels through a combination of modeling, simulation, and measurement techniques. It presents novel permittivity characterization methods for human skin and planar materials at sub-THz frequencies, overcoming phase calibration difficulties in free-space measurements. The study develops reference antennas at 28 GHz, 39 GHz, and sub-THz bands to systematically investigate hand effects on handset antennas. 

A key contribution is the validation of full-wave simulation models using radiation pattern measurements with real hands and hand phantoms. Additionally, an analytical model based on knife-edge diffraction and geometric optics is introduced, providing a computationally efficient alternative to full-wave simulations for predicting spherical coverage of handset antennas. These methods enhance the accuracy of wireless channel modeling at high frequencies. 

The results of this research contribute to the development of advanced handset antennas and wireless communication systems by improving the understanding of human-induced signal blockages. The validated models and measurement methodologies provide a foundation for future studies on hand-antenna interactions, material characterization, and wireless system optimization. 

The defense is open to the public. Welcome!

Key words: Handset reference antenna, human blockage, permittivity characterization, millimeter wave, sub-terahertz

Thesis available for public display 10 days prior to the defence at Aaltodoc. 

Contact:
bing.xue@aalto.fi 
https://www.aalto.fi/en/department-of-electronics-and-nanoengineering/antennas-and-propagation