A wireless transmission system comprising a main circuit board having a first controller and a first connector assembly associated therewith; a removable and replaceable radio frequency module for transmitting and receiving wireless data, wherein the radio frequency module includes a second controller, a first module connector assembly, and a second connector assembly that is configured to couple to the first connector assembly; a removable and replaceable diplexer module for sending and receiving the wireless data at different frequencies, wherein the diplexer module includes a storage element, a first waveguide port connector, and a second module connector assembly that is configured to couple to the first module connector assembly; and a transition waveguide module having a second waveguide port connector that is configured to couple to the first waveguide port connector.

A wireless transmission system comprising a main circuit board having a first controller and a first connector assembly associated therewith; a removable and replaceable radio frequency module for transmitting and receiving wireless data, wherein the radio frequency module includes a second controller, a first module connector assembly, and a second connector assembly that is configured to couple to the first connector assembly; a removable and replaceable diplexer module for sending and receiving the wireless data at different frequencies, wherein the diplexer module includes a storage element, a first waveguide port connector, and a second module connector assembly that is configured to couple to the first module connector assembly; and a transition waveguide module having a second waveguide port connector that is configured to couple to the first waveguide port connector.

A septum polarizer according to one embodiment can comprise a waveguide body and a stair-shaped septum, which is arranged in the longitudinal direction inside the waveguide body and divides the waveguide body into two parts, and has stepped parts of different heights so that a higher order mode can be reduced in a preset frequency band. In addition, a septum polarizer according to one embodiment can comprise: a waveguide body having a polygonal cross-section; a stair-shaped septum, which is arranged in the longitudinal direction inside the waveguide body and divides the waveguide body into two parts; and a pleated part arranged on the outer surface of the waveguide body, and thus a higher order mode can be reduced in a preset frequency band.