Synthesis and design of novel metamaterial radiation structures

Abstract

The present thesis deals with the design and practical implementation of novel netamaterial planar antenna structures based on Complementary Split Ring Resonator (CSRR) particles. As CSRR particles display a very attractive electrical performance when used as unit cell for metasurfaces, the authors of this thesis have proposed to implement such particles in waveguide lters. In this case, the possibility to design waveguide lters with lengths equal to the thickness of a metallic sheet is con rmed. Consequently, the proposed structure constitutes a signi cant reduction of the dimensions of the well-known resonant cavity waveguide lters coupled by irises. The behavior of CSRR particles within compact waveguide lter suggested the authors to use them as stand alone radiating elements. As expected, due to the reduced electrical volume of CSRRs, such particles exhibited low radiation e ciency. In order to improve the radiation e ciency, the idea to implement CSRRs inside a larger structure came to us. Measurement results con rm this hypothesis and raise the question to design multi-band antennas. In order to implement multi-band antennas, several CSRRs are inserted at di erent positions in the patch. It is then observed that the grouping of CSRRs can provide either multi-band operation or polarization rotation capabilities, when Electro-Inductive Waves (EIW) are supported. Finally, thanks to EIW propagation, the idea to use longer CSRR chains as radiating structures came to us. As an intermediate step, and in order to validate simulated results, a nite array composed of nine CSRRs is manufactured and partially tested. Though partial, this test results are very encouraging and motivate a more in deep measurement campaign. This campaign is expected to result into new publications on this topic. These results support the use of the proposed CSRR chains for the design of leaky wave antennas.