Design of single-ridge SIW power dividers with over 75% bandwidth

Waveguide structures have a constrained bandwidth due to their cutoff frequencies and presence of higher order modes. Ridged substrate integrated waveguides (RSIW) are low profile, low cost and planar that can be designed for wider bandwidth. In this paper, a two-way power divider based on RSIW is designed to extend bandwidth beyond that of conventional guides. The design utilizes a developed low loss GCPW to RSIW transition to feed the structure. Design was successfully extended to eight way splitter as well. The developed divider has almost a 75% bandwidth with better than 15dB return loss from 5 to 11 GHz. In particular, the splitter demonstrated excellent amplitude and phase imbalance of less than ±0.35 dB and ±7° within 5.5 to 9 GHz, respectively. Theoretical and experimental results are in good agreement.