Directional broadband planar slot antenna fed by dual-offset tri-plate lines on double-layer substrate in 20GHz band

UWB technologies are being applied to automotive radar systems in the quasi-millimeter wave band (24.25~29GHz). A broadband directional slot antenna is developed for array element of the antenna. The antenna is composed of a slot on the top of the double layer substrate which is fed electromagnetically from the dual offset tri-plate lines. Broad bandwidth is achieved by double resonances of the whole slot and the quasi slot between the dual offset feeding lines. The antenna was optimized by using electromagnetic simulator HFSS of the finite element method in 20 GHz band. The performance of the developed antenna was evaluated by simulation. The bandwidth of |S₁₁| less than -10 dB was 16 GHz (70%).