Substrate integrated waveguide hybrid coupler with integrated filter for radar applications

This paper proposes a substrate integrated waveguide (SIW) 180 degrees hybrid coupler with an integrated filter. This device operates at 24.1 GHz for radar applications and the filter removes the frequency of 22.1 GHz coming from the local oscillator. This device is the RF passive part of a single balanced diode mixer. The passive part has been designed, fabricated and measured.