Folded Corrugated SIW (FCSIW) Slot Antenna for Backlobe Suppression

A novel substrate integrated waveguide (SIW) slot antenna having folded corrugated stubs is proposed for suppressing the backlobes of the SIW slot antenna associated with the diffraction of the spillover current. The longitudinal array of the folded stubs replacing the SIW via-holes effectively prevents the propagation of the surface spillover current. The measured front-to-back ratio (FTBR) has been greatly (15 dB) improved from that of the common SIW slot antenna. We expect that the proposed folded corrugated SIW (FCSIW) slot antenna plays an important role for reducing the excessive backside radiation of the SIW slot antenna and for decreasing mutual coupling in SIW slot antenna arrays.