Differential radial power combiner using substrate integrated waveguide

A novel substrate integrated waveguide (SIW) differential radial power combiner design is presented based on changing the electric field polarity of selected probes, which greatly simplifies the design and modelling. The 180° out-of-phase characteristic between the selected two output ports is frequency independent, which is suitable for various broadband applications. To verify the differential operation, the 4:1 combiner (which can also be used as a power divider) based on the SIW is demonstrated experimentally. Good agreement between measured and simulated results indicate that the differential radial power combiner has low loss (<;; 1 dB), operational bandwidth (3.85-4.2 GHz), and excellent amplitude and phase imbalances are less than 0.03 dB and 1°, respectively.