Abstract:

In this paper the FD-TLM (Frequency-Domain Transmission Line Matrix) method is applied to model and analyze a 3D longitudinally loaded periodic waveguide. The study can be reduced to a unit cell which is limited by Floquet’s boundaries. Previous contributions using time-domain TLM (TD-TLM) in modeling waveguide discontinuities were interesting and still to be exploited in FD-TLM which is the aim of this work.

Abstract:

In this paper, the characteristics of a composite right- and left- handed (CRLH) transmission line unit cell are discussed. Characterization is based on the effective medium concept by using Nicolson-Weir-Ross method. This technique manipulates the scattering parameters obtained from full-wave simulation of the CRLH unit cell. The retrieval process is needed to determine the equivalent circuit model which consists of the series inter-digital capacitor (IDC) and shunt grounded stub inductor (SGSI) in asymmetric configuration. According to this method, the complex effective permeability and permittivity can fully define artificial structured Meta-materials, considered in general inhomogeneous mediums.

Abstract:

Due to the rapid growth in the use of wireless communication systems, there has been a recent increase in public concern regarding the exposure of humans to Radio Frequency (RF) electromagnetic radiation. This is particularly evident in the case of mobile telephone handsets. There is a need to develop techniques for reducing SAR in the design stage of mobile phone to meet exposure standards. It is important for portable devices to have a reduced SAR value. Previously, the insertion of a ferrite sheet between the antenna and the human head, the position of the antenna feeding point; the use of conductive materials (such as aluminum), and electromagnetic band gap (EBG) structures to design high performance devices were proposed as methods of reducing the SAR value. This paper aims to provide an investigation of the effectiveness of various available Specific Absorption Rate (SAR) reduction solutions.