Low-Profile Multibeam Beam-Scanning Antenna for Vehicular Radar Systems

In this work, a novel low-profile multibeam beam-scanning antenna (BSA) based on a Luneburg lens (LL) beamforming network (BFN) for vehicular radar applications is proposed. The antenna is composed of three parts, concluding seven microstrip line input ports, an LL BFN, and eleven high-scanning rate leaky-wave antennas. The gradient index of the LL beamforming network is achieved by discretizing the LL into a series of concentric rings filled with air. To obtain a larger scanning range of the BSA, the spoof surface plasmon polaritons transmission line is used to achieve higher scanning rate. The proposed antenna is designed in X-band. The simulated results demonstrate that the antenna achieves a beam-scanning range of -54° to 62° in the H-plane and a multibeam coverage range of 88° in the E-plane with the realized antenna gain more than 10 dBi from 8 to 11 GHz.