Analysis of Near-Field and Radiation Characteristics of a Mobile Phone in 4G and 5G Frequency Bands in the Presence of Shielding Structures

Abstract

This paper presents a numerical investigation of the near-field and radiation characteristics of a mobile phone operating in 4G and 5G frequency bands. The analysis is performed at 1800 MHz, 2600 MHz, and 3500 MHz in the presence of shielding structures composed of materials with different electromagnetic properties. Three representative materials, namely aluminum, FR4, and a carbon-loaded polymer, are considered in order to evaluate the influence of conductive, dielectric, and lossy shielding configurations on the electromagnetic behavior of the device. The mobile phone model and shielding structures are developed and analyzed using the WIPL-D EM simulation software. The effects of shield material, shield distance, shield position, and phone orientation relative to the shielding plate are investigated through a comprehensive parametric study. The near-field behavior is evaluated using the electric field while the influence of the shielding structures on the antenna performance is examined through reflection coefficient, gain and radiation pattern analysis. The obtained results provide insight into the interaction between shielding structures and mobile phone antennas operating in contemporary wireless communication bands and may serve as guidelines for the design of shielding configurations that reduce nearfield electromagnetic field levels while preserving acceptable antenna performance.