A Substrate Integrated Waveguide Planar Slot Array Antenna with Low Sidelobe Level

Abstract

A substrate integrated waveguide (SIW) slot array antenna with low sidelobe level (SLL) is proposed in this paper. The slot array contains a new method to make use of the internal mutual coupling between slots to achieve the desired current distribution with low SLL in the H-plane. In addition, to realize Dolph-Chebyshev distribution in the E-plane, a power divider is presented, including the design of SIWs with different widths, SIWs with corners bent in arcs, and T-junctions with two posts for the sake of achieving phase compensation, wide bandwidth, and high power-dividing ratio at the same time. By adding two extra posts to control the imaginary part of the impedance, a transition from conductor-backed coplanar waveguide (CBCPW) to SIW with tuning flexibility is applied to feed the antenna. The 64-element SIW slot array antenna is operated at 24 GHz with the simulation result of SLL around - 18.1 dB.