Skin Depth Q: Cellphone Rings in Cavity

  • Context: Undergrad 
  • Thread starter Thread starter Thierry12
  • Start date Start date
  • Tags Tags
    Depth Skin Skin depth
Click For Summary
SUMMARY

The discussion centers on the unexpected ringing of a cellphone placed inside a closed aluminum cavity, despite expectations set by the skin effect. The user noted that the cellphone was able to receive signals even though the enclosure was thought to be airtight. Key insights reveal that aluminum-to-aluminum contact does not guarantee a proper seal for electromagnetic interference (EMI) and electromagnetic compatibility (EMC) purposes. Effective sealing techniques such as contact fingers, soldering, and conducting gels are essential for preventing RF signals from penetrating the enclosure.

PREREQUISITES
  • Understanding of skin effect in RF signals
  • Knowledge of EMI/EMC design principles
  • Familiarity with materials used in RF shielding, particularly aluminum
  • Experience with enclosure sealing techniques
NEXT STEPS
  • Research effective EMI/EMC sealing techniques, including contact fingers and conducting gels
  • Learn about the skin effect and its implications for RF signal transmission
  • Explore the properties of aluminum as a material for RF shielding
  • Investigate the design considerations for creating airtight enclosures for electronic devices
USEFUL FOR

Electronics engineers, RF engineers, and anyone involved in designing enclosures for electronic devices, particularly those focused on minimizing electromagnetic interference.

Thierry12
Messages
25
Reaction score
0
I placed a cellphone in 2 half-spheres that i closed afterwards to create a metal cavity (aliminium 1mm) and called it (with another cellphone). The phone rang even if it wasn't supposed to considering the skin effect (wavelength were about 0,04m and i couldn't see any holes). Anyone has a clue why?
 
Physics news on Phys.org
RF can get through very small gaps.
When you said you 'closed them' unless you made an airtight seal (difficult without some fancy machining) you didn't really close them.
Cell phones are designed to pick up very-very weak signals.
 
When you're designing enclosures for EMI/EMC, particularly at those frequencies, aluminum touching aluminum doesn't count. You have to use things like contact fingers, solder, mechanical pressure, conducting gels, and so on.
This link will give you some considerations and examples
http://www.cotsjournalonline.com/home/article.php?id=100057
 
Last edited by a moderator:
Next time i will close them proplerly! ty
 

Similar threads

Undergrad Does a Fabry Perot cavity charge in discrete steps?
  • · Replies 12 ·
Replies
12
Views
4K
Graduate In light of new evidence, what might be behind the Casimir Effect?
  • · Replies 46 ·
2
Replies
46
Views
5K
What colors and attributes could alien flora & fauna have?
  • · Replies 15 ·
Replies
15
Views
6K
Writing: Input Wanted Generation Ship SFV Exodus: Revised Designs
  • · Replies 52 ·
2
Replies
52
Views
7K
Is my fictional Solar System stable and realistic?
  • · Replies 21 ·
Replies
21
Views
5K
Surface roughness in 2D sinusoidal corrugation
  • · Replies 1 ·
Replies
1
Views
5K
Futility of self-pride and indignation
  • · Replies 27 ·
Replies
27
Views
5K
Challenge Math Challenge - December 2018
  • · Replies 67 ·
3
Replies
67
Views
16K
Mathematica This Week's Finds in Mathematical Physics (Week 231)
  • · Replies 5 ·
Replies
5
Views
3K
Mathematica This Week's Finds in Mathematical Physics (Week 231)
  • · Replies 5 ·
Replies
5
Views
3K