Design and implementation of a planar 4×4 butler matrix in SIW technology for wideband applications

A broadband four-way Substrate Integrated Waveguide (SIW) Butler matrix was designed in Ku-band. In this structure, an SIW hybrid 3-dB coupler and crossover are designed as fundamental building blocks. Performances of the wideband components performances are presented and discussed. The matrix is fabricated and measured, excellent amplitude and phase characteristics are obtained over 3 GHz frequency band centered at 12.5 GHz which makes it very attractive for wideband multibeam antenna applications.