Sub-Terahertz Waveguide Antennas Based on Contactless Thin Metal Sheets

This paper presents the design, manufacturing, and measurement of waveguide antennas based on a contactless multilayer structure incorporating glide-symmetric electromagnetic band gap (EBG) technology to prevent leakage. The proposed multilayer waveguide technology is analyzed by examining the stopband behavior of the EBG and the propagation constant of the waveguide's fundamental mode. The paper demonstrates the scalability and reliability of this technology by developing and testing three slotted waveguide antennas operating at W-band (75–110 GHz), G-band (140–220 GHz), and J-band (220–330 GHz). The prototypes, fabricated using laser cutting and copper plating, show low manufacturing errors, stable performance despite variations in the air gaps between layers, and high efficiency, proving the feasibility of the multilayer waveguide technology for mmWave and sub-terahertz frequency applications.