A Low-Loss Ka-Band Waveguide To Substrate Integrated Waveguide Transition Based On Ridged Stepped-Impedance Transformer

A low-loss Ka-band transition from waveguide to substrate integrated waveguide (SIW) is presented based on ridge waveguide stepped-impedance transformer. This novel transition can operate across a full Ka-band (26.5 to 40 GHz) with an insertion loss lower than 0.59 dB and return loss over 14.2 dB. Furthermore, compared to existing transitions the introduction of ridges reduces the metal usage, resulting in weight reduction and offering an encouraging application for weight-sensitive satellite communications (SatComs).