×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

*
*
*
*

Thanks. We have received your request and will respond promptly.

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Waveguide Internal Surface Roughness

thread247-452137

Waveguide Internal Surface Roughness

Waveguide Internal Surface Roughness

(OP)
Hi there!
If anyone can clarify the relationship between propagation frequency and internal roughness level of a circular waveguide please?
Regards

RE: Waveguide Internal Surface Roughness

From first principles, these are presumably all in linear proportion:
  • Wavelength (inverse of frequency)
  • Size of waveguide (closest appropriate standard size)
  • Roughness requirements
There are probably some factors impacting loss that would not scale in linear proportion.

Speculation Alert -^ .

A Google search of the obvious search terms shows some scholarly articles on the subject.

RE: Waveguide Internal Surface Roughness

Frequency sets your skin depth (e.g., 0.66 microns @ 10GHz), right? So the roughness of your surface can/will have a major effect on how far the signal of interest travels (for a rough surface and a small skin depth, it has to travel over every peak/valley in the surface). Pretty easy to ignore at 1GHz, but difficult to ignore at 100GHz.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Waveguide Internal Surface Roughness

(OP)
Thanks MacGyverS2000. Yes frequency sets the skin depth. Please say what percent of surface roughness be of skin depth not to effect the propagation or say a single digit percentage of loss?

RE: Waveguide Internal Surface Roughness

Depends on the length of the wave guide doesn't it? All the waveguide I've seen is extruded and very smooth, but it was for only a few feet.

RE: Waveguide Internal Surface Roughness

For high-efficiency guides, they'll silver coat the inside since it has a slightly lower resistivity.

Dan - Owner
http://www.Hi-TecDesigns.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login

Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close