Waveguide Flange
Understanding Waveguide Flanges
Waveguide flanges are the connectors of the waveguide world. Unlike coaxial connectors (which use center pins and outer conductors), waveguide flanges join by mating flat surfaces with precise alignment, creating electrical continuity across the waveguide walls.
Flange Types
- Flat (cover) flange: Simple flat surface with bolt holes. Choke flange must be on the opposite side. Least expensive.
- Choke flange: Has a concentric groove (choke joint) that provides electrical continuity without requiring perfect surface contact. Reduces leakage at the joint.
- UG-series (MIL-spec): Precision flanges with alignment dowel pins. Examples: UG-599 (WR-90), UG-385 (WR-42).
- CPR: Commercial standard with grooved face and guide pins. Less expensive than UG.
Flange Mating
- Flat-to-choke: Standard connection. Choke provides RF continuity.
- Flat-to-flat: Requires excellent surface finish and high torque.
- Choke-to-choke: Not recommended (two choke grooves can resonate at some frequencies).
Frequently Asked Questions
What is a waveguide flange?
A waveguide flange is the mechanical interface for connecting waveguide sections. Types include flat (cover), choke (with groove for electrical continuity), UG-series (precision MIL-spec), and commercial CPR flanges. Proper alignment is critical for low loss.
What is a choke flange?
A choke flange has a concentric groove that acts as a quarter-wave short, providing electrical continuity across the joint without requiring perfect metal-to-metal contact. One flat and one choke flange is the standard mating configuration.
How do you choose the right flange?
The flange must match the waveguide size (WR designation). Standard recommendations: UG-series for measurement and precision applications, CPR for commercial, and flat flanges for the mating side. Always pair flat with choke for best performance.