Gain enhancement by planar capacitive soft cavity at millimeter wave

In this paper, we propose to use a planar capacitive soft cavity, at millimeter wave, to enhance the gain of a cylindrical DRA. A 4 dB minimum gain enhancement is observed at 57 GHz. Even without superstrat, the cylindrical DRA have a minimum of 10.2 dB and a maximum of 11.2 dB over the whole ISM band (57GHz - 64GHz). The radiation pattern shows that the cavity is able to focus in one beam even when the DRA radiation pattern has two beams. This cavity can be used for beam steering/reconfigurable radiation pattern antenna. CST Simulations confirmed the principle of the gain improvement by the proposed capacitive soft cavity.