A Hollow Rectangular Coaxial Line for Slot Array Applications Fabricated by Diffusion Bonding of Laminated Thin Metal Plates

A hollow rectangular coaxial line is designed for the 60-GHz band and fabricated by diffusion bonding of laminated thin metal plates. A low transmission loss of 0.036 dB/cm is confirmed at 60 GHz by measurement in a designed rectangular coaxial line. The suspended inner conductor is supported by a thin plate. A longitudinal slot excited by the metal support and its linear array are presented. The proposed structures are verified by comparing the measured results with the designed ones. The 1.5% bandwidth of the linear array for reflection below -14 dB is obtained by the measurement.