Quad Element Metamaterial based Antenna for C and X band Application with Improved Diversity Characteristics

In this paper a metamaterial loaded UWB MIMO operating in C and X band is presented. The proposed design uses hexagonal fractal structure with partial ground plane to achieve UWB characteristics. The design is utilized for four element MIMO to offer better diversity performance with relevant compactness. The isolation between orthogonally placed MIMO elements is achieved below -15dB in entire resonance band from 6 GHz to 12 GHz with inter-element separation of 0.33λg giving the overall dimension of 93mm x 93mm x 1.6mm. The isolation is further enhanced by using a single negative (SNG) metamaterial with MIMO. The obtained results were verified by fabricating the proposed design in low-cost FR-4 showing the resonance from 6-12 GHz with good impedance matching and isolation below -30 dB in entire resonating band. The uniqueness of the proposed design is much less volume despite the metamaterial superstrate placed 1.5 mm above the MIMO. The 2D radiation pattern for E field and H field co and cross polarization shows more co-polarization and less cross polarization with almost omnidirectional radiation pattern.