Substrate integrated waveguide differential filtering power divider with good common‐mode suppression and high selectivity

A filtering differential power divider based on the substrate integrated waveguide (SIW) technology is proposed for the first time, featured by good common‐mode suppressions and high selectivity. A rectangular SIW cavity, which is connected with differential inputs and operates in a balanced diagonal TE 102 mode, is utilised to achieve the power division function. It also works with rectangular SIW cavities, which resonate in balanced TE 102 modes, to obtain good common‐mode suppressions for all cases. Meanwhile, electric negative cross‐couplings are introduced to improve the frequency selectivity of the proposed filtering power divider. A prototype operated in the X‐band has been developed for a demonstration. Good agreement between simulated and measured results is obtained.