What is the difference between WR designations and the corresponding frequency ranges?
Standard Waveguide Band Reference
The standard WR waveguide series provides a complete set of waveguide sizes covering frequencies from below 1 GHz to above 300 GHz. Each waveguide size is optimized for a specific frequency band with approximately 40% bandwidth. The WR number directly encodes the physical dimension: WR-90 has a broad wall dimension of 0.900 inches (22.86 mm).
The standard operating ranges overlap slightly between adjacent WR sizes, allowing users to choose the size that best fits their needs. For example, at 12 GHz, both WR-90 (8.2-12.4 GHz) and WR-75 (10.0-15.0 GHz) can be used. WR-90 offers more power handling and lower loss but is physically larger.
Each WR size has associated standard flanges, components (adapters, bends, transitions, loads, attenuators), and test equipment. Using standard sizes ensures component availability and interchangeability. Custom waveguide sizes are sometimes specified for unique applications but suffer from the lack of commercially available components.
Frequently Asked Questions
What are the most commonly used sizes?
WR-90 (X-band): radar, satellite communications. WR-42 (K-band): satellite uplinks, 5G backhaul. WR-28 (Ka-band): satellite earth stations. WR-10 (W-band): automotive radar, point-to-point links, scientific research. These sizes account for the majority of waveguide component sales.
What about reduced-height waveguide?
Reduced-height (half-height) waveguide uses the same broad dimension (a) but half the narrow dimension (b). This provides the same frequency range in a lower profile but with higher attenuation and reduced power handling. It is used in space-constrained applications.
Can I convert WR designations to metric?
Yes. Multiply the WR number by 0.254 to get the broad dimension in mm. WR-90: 0.90 × 25.4 = 22.86 mm. WR-10: 0.10 × 25.4 = 2.54 mm. International standards use metric (R) or IEC designations instead of WR.