4×4 Butler-Matrix based Beam Steering Antenna Systems using Substrate Integrated Waveguide

In this paper, two innovative 4×4 Butler matrix-based antenna system designs are proposed for mmWave/5G applications which are capable of beam scanning/steering at Ka-band. By utilizing the multilayered substrate integrated waveguide (SIW) structure, the size of antenna system design is miniaturized. Beam forming can be achieved due to the application of beam forming network (BFN) based on Butler matrix. Designed beam steering antenna systems with miniaturized 4×4 Butler matrix show frequency range from 26 GHz to 38 GHz. Overall design structure sizes of two designs are 114.3 mm × 23.8 mm × 2.2 mm and 112.3 mm × 18.0 mm × 3.3 mm respectively.