A Broadband Gap Waveguide-Based Magic-T Junction for Millimeter-Wave Applications

A broadband magic-T junction for millimeter-wave applications is proposed in this article. Gap waveguide technology is employed to overcome fabrication and assembly challenges at millimeter-wave frequencies. The measured results for a fabricated prototype are in good agreement with the simulations. The measurements indicate that the fabricated structure exhibits 28% impedance bandwidth and isolation better than 69 dB between E- and H-arms in the Ka-band. In addition, the measured coupling level between the collinear arms is less than −18.6 dB. The proposed structure is compact and simple, has high power and low loss, and is suitable for low-cost fabrication to utilize in a wide variety of millimeter-wave and microwave applications.