On Target Detection and Imaging Sensitivity by Using LHM Flat Lens

In this paper, the detection and imaging sensitivity by using LHM flat lens to the target shape and material is studied. The target shape varies from cylinder, square, isosceles-triangle and stripe. By scanning the transmitting and receiving microwave antenna (T/R) pair on the other side of the LHM lens without target, the image is reconstructed. It shows that the rough shape of the target can be achieved. For a small cylinder target, the image shape is stretched along the depth direction. For the square targets, the image reflects that edges paralleling to the surface of the LHM flat lens induce stronger reflection field intensity indicating the possible position and the edge length of the target. For an isosceles-triangle target that its base edge is placed toward the surface of the flat lens with its vertex angle backward, it is shown that the backward vertex angle make a weaken reflection field intensity. By comparing with the image of a stripe target in the same dimension sizes along two- axis, it is confirmed that the edge of target paralleling to the surface of the LHM flat lens leads to stronger reflection. The impact of different material on the target detection and imaging are also explored, it is found that for a small cylinder target the material difference will definitely induce different reflection field intensity, and the perfect electric conductor (PEC) does not promise the most intensified reflection field. For the lossy material, the conductivity parameter also affects reflection field intensity, but the 3dB threshold of the maximum field intensity is almost unchanged.