W-Band 2-D Multibeam Antenna Based on Rectangular Microcoaxial Lines

This paper presents a W-band 2-D multibeam antenna based on rectangular microcoaxial lines (RµCL). A 2-D (RµCL). beam-forming network (BFN) for eight beams is proposed, which consists of four 90° couplers, four phase shifters (named PS to PS4, respectively), and two 4 × 4 Butler Matrix. Combined with a 2 × 4 cavity-backed antenna array, the multibeam antenna can achieve eight (2 × 4) scanning beams on 2-D with stable gains for wide coverage and the simulated gains of all the beams are better than 12.6 dBi.