Radiation of a handset monopole antenna in the presence of a finite shielding sheet for the purpose of SAR reduction

The electromagnetic field radiation from monopole handset antennas in the presence of finite shielding structures is investigated. This work is motivated by the increasing concern and efforts to design antennas with SAR reduction. In contrast from previous works that focus on directional antennas for minimizing the radiation on a human and reducing the SAR at the cost of poorer reception since the base station sites to be connected with the handset are directionally restricted, the present work intends to reduce the very near field radiation strength, which is the major cause of high SAR, while, in the mean time, retain as much as possible the far field radiation characteristics of omni-directional antennas based on the shielding techniques. The near field reduction on the human side is achieved via the applications of shielding. The study focuses on the propagation mechanism and the shielding of the near field radiation from antennas directly. The shielding structure can be integrated with the antennas to provide better shielding effectiveness.