Design of Chip Resistor Loaded Metamaterial Based Electromagnetic Structures

Abstract

Due to the unique electromagnetic (EM) characteristics, metamaterial structures (MMSs) have achieved increasing attention of the researchers. MM are the artificial periodic structures with lattice constants that are much smaller than the wavelength of the incident radiation. Therefore providing negative refractive index characteristics. A wideband MMSs using traditional and Nature Inspired (NI) Conducting Geometries (CG) loaded with lumped resistor have been designed in the range of 2 to 18 GHz. The MMS consists of a resistor loaded CG, a dielectric sheet and a metallic ground.NI –CGs can be employed for the fulfilment of broadband absorption due to its attractive features like space-filling, multiband resonance, and self-similarity. The EM characteristics of NI-CGs depends on CG shape, CG iteration order and dielectric constant of the substrate. Moreover, an incorporation of chip resistors can further improve the reflectivity characteristics of NI-CG based MMSs. The results show that the MMS covers the wide frequency range with reflection loss below -10 dB at normal incidence. The broadband absorption is mainly resulted from the strong EM resonance. The obtained result reflects the potential of lumped resistor based MMSs for distinct EM applications. Various shapes of CG analysed and their complexity have been taken into account in order to improve the S11 characteristics. Efforts were made in order to design the MMSs for low frequency applications by inserting spacer foam in between the dielectric substrate layer and the conducting sheet. Different physical parameters are studied for these geometries, and the working mechanisms behind these phenomena are explained in this thesis. Some potential applications of these structures are also discussed. The purpose of this study was to develop new CG based MMS designs to maximize the bandwidth of structure. A Triple Square (TS) -MMS structure is found to accomplish more extensive peak RL value with wide bandwidth when contrasted with NI-CGs.