WR-90 Waveguide to Coaxial Adapters from Fairview Microwave are also known as waveguide to coax transitions. Type N, SMA waveguide to coaxial adapters are in-stock and available for same day shipment. Fairview WR-90 Waveguide to Coaxial Adapters have a maximum frequency of 12.4 GHz and a max VSWR of 1.25. WR-90 Waveguide to Coaxial Adapters have a connector body material of passivated stainless steel.