Blockage reduction of rhombic cylinders using meta-surfaces

Blockage caused by struts with rhombic cross sectional shape and relatively large width can be reduced by coating them with artificial surfaces. Two different types of coating solutions which reduce blockage simultaneously for TE and TM cases were proposed. The first solution is based on hard surfaces made with narrow metallic strips and it has been proven how parameters such as the strip period and the rhombus length are critical for TE performance. The second solution (using a mushroom-type meta surface)has very good performance for TE case around 8 GHz with a very low blockage width over a significant bandwidth. This represents a new blockage reduction technique produced by a TM surface wave (relative to the surface normal) propagating around the strut. The performance for TM case is also good around 8 GHz, but within a very narrow band.