Beam Switchable Antenna Array Design by Rotman Lens with SIW Feeding Lines for Vehicular Applications

In this study, the substrate integrated waveguide is used to design the Rotman lens, and the multi-layer board technology is used to integrate the antenna array. Its operating frequency is set from 76GHz to 81GHz. Since the transmission loss of the operating frequency electromagnetic waves is more serious, the Rotman lens uses a dielectric waveguide design, and the antenna will adopt an array form to increase the gain and make up for the loss caused by the transmission path. This study uses a multilayer board to integrate the antenna array and the beam switchable circuit, which greatly reduces the size, and the three beams have a gain of nearly 18dBi in 0 and ±18 degrees separately.