A Novel Millimeter Wave Multiple Beam Antenna with SIW Butler Matrix

Abstract

A millimeter multiple beam antenna is proposed, which is fed with substrate integrated waveguide (SIW) Butler matrix and unequal power divider. The 4 × 4 Butler matrix is composed of hybrid coupler, cross coupler and phase shifter. The phase delay is controlled with the propagation path of electromagnetic power, and the unequal power divider is realized with the insertion of plated via. The SIW slot antenna array is connected to the cascading circuit for good impedance match. The side lobe level (SLL) of antenna pattern is apparently reduced with the unequal distribution of weight magnitudes. This multiple beam antenna is suitable for the equipment in the future mobile communication system.