This article deals with multilayer substrate integrated waveguide (SIW) six-port junctions with embedded carbon resistive films. SIW six-ports usually employ reactive power dividers, which degrade the amplitude and phase balance when the six-port is terminated with mismatched power detectors. The associated impairments are studied and two SIW six-port junctions with improved isolation and output matching are designed for K-/Ka-band applications to overcome these limitations. The proposed designs differ with respect to the configuration of the output ports making the underlying six-port topology applicable for different layout requirements. Measurements of the fabricated components validate the concept. The six-ports are compact, fully shielded and can be integrated in multilayer printed circuit boards.
