Speaker
Description
The international guidelines for human exposures to electromagnetic fields had been revised, introducing a new metric referred to as absorbed power density (APD) as the basic restriction in the frequency range from 6 to 300 GHz. The APD measurement using the conventional high-loss tissue-equivalent phantom at high frequencies above 6 GHz presents significant challenges due to short penetration depth in the millimeter wave region. To overcome this difficulty, authors have proposed a method for reconstructing APD on the skin surface by near-field measurements utilizing a low-loss phantom. However, the previous study was conducted only at 28 GHz, leaving the usability of the phantom at other frequencies remain uncertain. In this study, the optimization of a low-loss phantom for APD evaluation which was previously conducted at 28 GHz, was extended to 40 GHz. Additionally, the usable frequency bandwidths of the phantoms were evaluated within the range of 24–30 GHz and 36–44 GHz to cover the several candidates of the 5G communication systems. As a result, the low-loss phantom optimized at 28 GHz has a dual-band property that is 24.9 - 25.5 GHz (0.6 GHz) and 27.8 - 28.6 GHz (0.8 GHz). In addition, the low-loss phantom optimized at 40 GHz observes a multi-band property, namely at 36.0 GHz ~ 36.8 GHz (0.8 GHz), 39.4 ~ 40.7 GHz (1.3 GHz) and 43.0 ~ 44.0 GHz (1 GHz).
