Leaky Coplanar Waveguide Antenna with Tunable Beamwidth and Radiation Angle Using Composite Right/Left-Handed Materials

Abstract

A new field of physics has appeared with the emergence of materials known as "Left handed materials" (LHM) or "metamaterials". These materials show very particular characteristics. Their index of refraction has a negative value, which results in the reversal of Snell’s law. Whereas, in traditional material the Poynting vector S always forms a right-handed triplet with E and H (S = E ∧ H). In the left handed media, the Poynting vector S and the wave vector K are in opposite directions. Thus, the wave moves in the direction opposite to the direction of the energy flow: phase speed and group speed are anti-parallel. Therefore, a left-handed media is artificial and does not exist in nature. Indeed, when these materials are inserted into a guided wave device, one obtains the backward-wave effect. The goal of this work is to study more in details this physical phenomenon. To undertake this study, this paper presents also the design of a 10 GHz beam-scanning CPW-Antenna fabricated on metamaterial support.