Design of planar matching loads for traveling-wave-fed SIW slot arrays

This paper presents a novel planar matching load for travelingwave-fed substrate integrated waveguide (SIW) slot arrays. The load consists of a planar grounded coplanar waveguide (GCPW) matching load and a planar GCPW to SIW transition which makes the GCPW matching load compatible with the SIW. In the GCPW matching load a high frequency resistor is used to dissipate the remaining power. A traveling-wave-fed SIW slot array with the novel load is designed, fabricated and measured. The measurement results show the proposed planar matching load performs well over a wide band 24.2–26.0GHz, and reflection coefficient and side lobe level (SLL) of the array is significantly reduced comparing with the array with no load.