ENHANCEMENT OF A MICROWAVE RADIOMETRY IMAGING SYSTEMʹS PERFORMANCE USING LEFT HANDED MATERIALS

Aiming at the enhancement of a non invasive Microwave Radiometry Imaging Systemʹs (MiRaIS) attributes, Left Handed Materials (LHM) with negative permittivity and negative permeability simultaneously, have been utilized. The optimization of the system focusing properties is being theoretically explored, implementing a semi-analytical Greenʹs function technique and different matching structures. In the framework of this analysis the head is modeled by a double layered cylinder while a dielectric cylindrical layer consisting of LHM is placed on the surface of the human head model with a view to achieve focusing improvement inside the brain. Numerical code executions have been conducted for two different operating frequencies (0.5\,GHz and 1.0\,GHz) and for matching layers of various values of thicknesses and electromagnetic properties. The numerical results for the electric field distribution inside the head model, presented in this paper, verify that the LHM can provide an increased sensitivity of the system focusing properties and thus improve its overall performance.