Predicting Over-the-Air Performance Using a Hand Phantom With Large Dielectric Flexibility

This article developed a hand phantom with a large dielectric deviation from the target values, which can be used to estimate over-the-air (OTA) performance just like the Cellular Telecommunications and Internet Association hand phantom. In this article, the dielectric properties were adjusted by varying the graphite composition in the carbon-loaded silicone. Numerical simulations were used to determine the appropriate material recipe with the aid of the numerical models of four mobile devices operating from 870 to 2700 MHz, using both top and bottom antenna configurations. The results estimated that the material with a difference of 44.65% ± 20.15% (mean ± standard deviation, the maximum value is 77.97%) and 6.79% ± 3.35% (mean ± standard deviation, the maximum value is 9.43%) from the target conductivity and relative permittivity, respectively, provided the maximum deviation of 1.82 dB in the case of total radiated power (TRP) and 1.98 dB for total isotropic sensitivity (TIS). Accordingly, the molded hand phantom was validated with mechanical and OTA tests (maximum error below 1.30 and 1.80 dB for TRP and TIS, respectively). The results demonstrated that using the material with a larger dielectric deviation than the prescribed standard can be used to fabricate hand phantom for predicting the OTA performance. The findings shed light on designing and manufacturing of the hand phantom for in-house research and development purposes.