Compact 2-D Scanning Multibeam Array Utilizing the SIW Three-Way Couplers at 28 GHz

A compact two-dimensional (2-D) scanning multibeam array operating at 28 GHz in a substrate integrated waveguide technology is proposed, designed, simulated, and fabricated in this letter. To achieve better compactness, three-way couplers, instead of traditional Butler matrices, are applied here to form 2-D scanning beam-forming network. By doing so, the occupied area can be significantly reduced. After joining to the radiation portion, a 2-D scanning multibeam array allows for 3 × 3 beam steering in two orthogonal planes is fabricated and measured to test whether the measured results agree well with the simulation.