Single/ Multi Beam Antenna Using Genus Holographic Surface for MIMO Applications

Single, and multi-beam genus hologram antennas are investigated using the high-impedance surfaces properties. The antenna consists of hexagonal patches of varying sizes arranged in a periodic pattern according to the required beams direction. The patches periodicity controls the direction and number of radiated beams from the array. Tapered microstrip transmission line is used to excite the antenna at its end. The proposed antenna has the ability of beam scanning from 33 ^o to 64 ^o at frequencies 13 to 17 GHz with peak gain of 20.6 dBi and high efficiency of 87%. Dual beam antenna at different angles of ( θ ₁  = 30 ^o , θ ₂  = 40 ^o ), ( θ ₁  = 60 ^o , θ ₂ =-60 ^o ) are obtained at f  = 15 GHz. Antenna with four beams at 120 ^o , 60 ^o , -60 ^o , -120 ^o is designed using a two layers genus structure with gain of 15.2 dBi at 16 GHz. The proposed hologram antenna is applied in MIMO structure with compact spacing between two antennas of 4.7 mm. Parasatic elements are used to reduce mutual coupling between MIMO antennas. The hologram antenna is studied in two conformal cases of longitudinal and transverse.