A modified compact Y-junction substrate-integrated waveguide (SIW) four-way power divider (PD)/combiner is proposed in this paper. The proposed approach is based on the traditional Y-junction waveguide. By using direct transition structure from SIW to half-mode SIW, four-way PD that provides equal power split to all four output ports is achieved. The even- and odd-mode equivalent circuits are given to analyze and design the PD. The measured results validate the proposed design methodology and show good agreement with the simulation results. The measured 17 dB return loss bandwidth and 1.2 dB insertion loss bandwidth of this four-way PD are both about 2.5 GHz.
