Handset Reference Antenna Array Design, Fabrication, and Application to Hand Effect Study at Sub-THz

The sub-Terahertz (sub-THz) frequency range, 100 GHz-300 GHz, has garnered significant attention in the wireless communication community for its potential to meet the growing data rate demand. It has been known that users' body effects on mobile handsets make a direct impact on the quality of the communication link, but their evidence and analysis models at sub-THz are non-existent. To fill in the knowledge gap, we developed two reference antenna arrays at sub-THz frequencies for the purpose, which have clear main beams and small ripples in radiation patterns, high cross-polarization discrimination, and easy integration with a handset-device-sized metal housing. The two arrays serve two orthogonal polarizations. When using the reference arrays for the antenna-hand interaction study, we first justify the use of hand models with a homogeneous complex permittivity at 140 GHz. Performance of the manufactured reference antenna arrays, held by the hand of a human subject, is then evaluated experimentally for comparisons with that from our simulation models of the antenna arrays and the hand. The maximum difference of the arrays' realized gains, when comparing simulation and measurement, is about 0.85 dB in the spherical coverage statistics. The comparison demonstrates the validity of our antenna-hand model for their interaction study at around 140 GHz.