You are designing a 4.9 GHz microwave system that is using rectangular waveguide from the transceiver to the inside wall of the shelter and an antenna using elliptical waveguide from the antenna to…

An elliptical waveguide pass-through is designed to route elliptical waveguide through a physical barrier such as a wall without transitioning between waveguide cross-sectional types.

An elliptical waveguide clamp is a mechanical support and fastening hardware used to secure waveguide runs along a tower or structure, not to electrically interconnect two different waveguide geometries.

An elliptical waveguide connector is specifically engineered to transition between two different waveguide types - in this case, the rectangular waveguide running from the transceiver to the inside shelter wall and the elliptical waveguide running from the outside wall up to the antenna. The connector maintains impedance continuity and minimizes insertion loss at the transition point between the two geometries, making it the correct specification for this interconnection.

An elliptical waveguide flange is used to couple two sections of the same elliptical waveguide together end-to-end and is not designed to interface between rectangular and elliptical waveguide types.