Low RCS and Broadband ME Dipole Antenna Loading Artificial Magnetic Conductor Structures

Abstract

A design for low radar cross section (RCS) and broadband magnetic-electric (ME) dipole antenna is proposed. Minkowski-like fractal metal patches printed on the substrate form the electric dipoles, four metallic vias connected to the radiation patches and the metal ground form the magnetic dipoles. The whole antenna is connected with an L-shaped feeding structure which excites electric and magnetic dipoles simultaneously. Meanwhile, two different structure AMC cells with a 180° (±30°) phase difference in a broadband frequency region are designed as a chessboard and loaded around the ME antenna radiation patch. Numerical and experimental results incident the antenna bandwidth is 42.4% from 8.0GHz to 12.3GHz, covering the whole X band. Moreover, the RCS is reduced remarkable in a broad frequency range from 6.5GHz to 15.5GHz (81.8% relative bandwidth) when compared to conventional ME antenna. After loading AMC structures, the antenna still keeps advanced performances such as stable gain and almost consistent pattern in E and H plane.