A four-element compact wide-band optically transparent MIMO antenna with a full ground plane is proposed. The four elements transparent MIMO system has a compact size of 24×20 mm 2 with the undivided ground plane as most of the real-time systems demand a common reference. The complete antenna system achieves around 85% transparency due to a combination of AgHT-8 and Plexiglas which forms the transparent conductive patch/ground and substrate, respectively. The antenna geometry leads dual-band operation ranging from 24.10-27.18 GHz (Impedance bandwidth = 12%) and 33-44.13 GHz (Impedance bandwidth = 28.86%) targeting the mm-wave 5G applications. The 4-element antenna system achieves isolation between inter-elements > 16 dB and maximum gain value of greater than 3 dBi with more than 75% efficiency. The proposed transparent MIMO antenna is evaluated in terms of diversity gain (DG), envelope correlation coefficient (ECC), total active reflection coefficient (TARC), and mean effective gain (MEG) where decent MIMO performance with isolation more than >16 dB between the adjacent and other elements is achieved. Transparent MIMO antenna achieves directional patterns for the operating band with the value of DG > 9, ECC < 0.1, TARC value less than-15dB, and the ratio of MEG within the agreed limit of ±3 dB confirming acceptable MIMO/diversity performance.

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A new approach to make low-density and high-porosity graphene foams in film form is presented. The foam thickness can be readily tuned. The graphene foam has excellent electrical conductivity and is hydrophobic. It provides superior EMI shielding and rapid absorption of organic solvents. CVD of few-layer graphene on porous Cu/Ni generated by electrodeposition of Ni on Cu followed by heat treatment and dissolution of Cu/Ni yields the graphene foam by a method that appears to be scalable to mass production.

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This paper presents a systematic approach to the optimum placement of direction finding (DF) antennas in a harsh platform environment. A circular array with omni-directional elements is considered for azimuthal direction of arrival (DOA) estimation based on the multiple signal classification (MUSIC) algorithm. The element positions are optimized by the use of a genetic algorithm (GA) in conjunction with the FEKO electromagnetic simulator. The proposed approach is first tested with a generic platform shape. It is then extended to a more realistic military aircraft model with a strong scattering object. The optimized results show a significant performance improvement over the uniform circular array in both platform environments. Index Terms-Antenna placement, direction finding (DF) antenna, direction of arrival (DOA) estimation, genetic algorithm, multiple signal classification (MUSIC) algorithm, platform effect.