Coaxial line and waveguide are two types of transmission line widely used for signal transferring in RF and microwave area. Waveguide-to-Coax adaptors are the Intermediate conversion structures connecting these two types of transmission line, which are largely used in many systems such as radar, wireless communication, and ATE. WG-to-coax adaptors are generally designed to “right angle” and “end launch” two types, aiming to introducing as little reflection thus insertion loss as possible. Seeking perfect design plus rigorous engineering process make Trigiant mmW's WG-to-coax adaptors outstanding in return loss performance.