I. Introduction
More recently, high performance millimeter wave (MMW) antennas oriented to high-speed wireless communication scenarios has become a research hotspot. In this sense, conventional waveguide antennas are confronted limited applications due to its high profile and weight. Planar antennas with low profile and light weight have shown huge advantages, they can be fabricated at a lower cost, and can be easily integrated in practical applications. Typical planar waveguide such as substrate integrated waveguide (SIW) fabricated by PCB have been well reported [1]-[2] and MMW antenna arrays using SIW feeding networks are also studied extensively [3]-[10]. The SIW slot antenna arrays proved to be good candidates for low sidelobe applications such as short-range radar applications or satellite platforms.