A Broadband Coaxial Line-to-SIW Transition Using Aperture-Coupling Method

Abstract

The letter demonstrates a coaxial transmission line-to-substrate integrated waveguide (CT-SIW) transition using aperture-coupling approach. The method broadens the bandwidth (BW) and reduces the transition insertion loss (IL). Two coaxial line supports with apertures for coupling are attached at the ends of substrate integrated waveguide (SIW). The copper inlaid of the apertures increases coupling of the coaxial line to SIW and can be controlled by the aperture length and the length of the line wire put in the aperture. The transition was designed, fabricated, and experimentally evaluated. The transition provides the measured 10 dB return loss (RL) fractional BW (FBW) of 104.3%, and 15 dB RL (FBW) of 78.06%. The IL of 0.37 to 0.87 dB at 19.63–62.7 GHz frequency range was obtained. The measured results are well correlated with the simulated ones.