Out-of-phase filtering power divider using rectangular SIW cavity

Co-design of an out-of-phase power divider and a bandpass filter is investigated in this paper. Using a rectangular substrate integrated waveguide (SIW) cavity, a two-way multi-layer out-of-phase power divider and a filtering power divider are designed, fabricated, and measured. A bandpass filter is embedded in the power divider to provide out-of-band rejection. Simulated and measured results agree very well in the operating band. Measurement results show that the insertion loss of the out-of-phase power divider and the filtering power divider is approximate 0.7 dB and 1.2 dB, respectively. For both two structures, amplitude imbalance is less than 0.2 dB and phase imbalance is less than 5 degree.