Axial Corrugated Choke Ring for Offset Parabolic Reflector

An axial metallic corrugated choke ring is introduced as an intermediary component between the feed horn and reflector. The choke ring with its concentric grooves and ridges acts as a surface wave suppressor, blocking the propagation of surface waves that would otherwise cause harmful sidelobe and backlobe radiation, thereby improving antenna performance without compromising the basic radiation functionality.

The choke ring structure converts the potentially harmful surface wave propagation into a beneficial effect by using the corrugated geometry to create RF choke effect. The concentric grooves and ridges transform the surface wave energy into evanescent fields that decay rapidly, turning what would be harmful radiation into a mechanism for suppressing unwanted lobes and improving overall antenna performance.

The choke ring is segmented into concentric grooves and ridges, dividing the continuous structure into discrete periodic elements. This segmentation allows the structure to suppress surface waves across a broad frequency range while maintaining a relatively simple overall geometry. The periodic segmentation creates multiple reflection points that interfere destructively with surface wave propagation.

The choke ring employs a curved, annular geometry with concentric circular grooves and ridges. This curvilinear structure is better suited for rotational reflector assemblies than straight linear structures, as it maintains symmetry and consistent performance throughout the rotation. The curved geometry naturally follows the rotational symmetry of the reflector assembly, reducing the need for additional complex components.