Author Topic: How to fight over the skin effect on home made antennas ???  (Read 2945 times)

0 Members and 1 Guest are viewing this topic.

Offline Free_WiFiTopic starter

  • Regular Contributor
  • *
  • Posts: 226
  • Country: it
  • https://tinyurl.com/y5nhpt2x
How to fight over the skin effect on home made antennas ???
« on: April 04, 2019, 12:50:33 pm »
I'm rambling/zapping around the net and there's thousands of beautiful pcb patch antennas...i really wish to make some for my self....
but the problem of the skin effect at 2 ghz 5ghz is totally ripping off the purpose to make at least one of them.

Do you know some kind of cheap plating material or some kind of trick to fight the skin effect ?

Thanks you very much.
« Last Edit: April 04, 2019, 01:50:49 pm by Free_WiFi »
 

Offline Free_WiFiTopic starter

  • Regular Contributor
  • *
  • Posts: 226
  • Country: it
  • https://tinyurl.com/y5nhpt2x
Re: How to fight over the skin effect on home made antennas ???
« Reply #1 on: April 04, 2019, 12:54:22 pm »
P.S I also thought to use some kind of sputtering machine with the graphite brick,so i could be able to plate the copper surface with some kind of graphene layer...
 

Offline Dataforensics

  • Supporter
  • ****
  • Posts: 136
  • Country: gb
Re: How to fight over the skin effect on home made antennas ???
« Reply #2 on: April 04, 2019, 01:39:45 pm »
Used to use silver plated copper wire many years ago when I was still into amateur radio.
There must be silver plating solutions around.
 

Offline Free_WiFiTopic starter

  • Regular Contributor
  • *
  • Posts: 226
  • Country: it
  • https://tinyurl.com/y5nhpt2x
Re: How to fight over the skin effect on home made antennas ???
« Reply #3 on: April 04, 2019, 01:53:06 pm »
My own problem is that i'm total 0 in chemicals ... so basically i need your help to figure out how i can going forward in this kind process.
 

Online dmills

  • Super Contributor
  • ***
  • Posts: 2093
  • Country: gb
Re: How to fight over the skin effect on home made antennas ???
« Reply #4 on: April 04, 2019, 02:15:42 pm »
Start by calculating the actual effect of the skin effect, with a reasonably thick trace it is less then you think!
Usually dielectric losses will vastly exceed skin effect  losses in the mid microwave region.

Note that for a line over a ground plane, the skin that matters is the one facing the ground plane, not the one on the top of the board!

If I was really bothered, immersion silver is a standard finish from PCB shops.

Regards, Dan.
 
The following users thanked this post: Free_WiFi

Online radiolistener

  • Super Contributor
  • ***
  • Posts: 3282
  • Country: ua
Re: How to fight over the skin effect on home made antennas ???
« Reply #5 on: April 04, 2019, 06:28:24 pm »
I think skin effect is not an issue here, the main problem will be dielectric loss in the PCB material.
 

Offline T3sl4co1l

  • Super Contributor
  • ***
  • Posts: 21606
  • Country: us
  • Expert, Analog Electronics, PCB Layout, EMC
    • Seven Transistor Labs
Re: How to fight over the skin effect on home made antennas ???
« Reply #6 on: April 04, 2019, 06:33:05 pm »
People seem to be making them successfully without regards to skin effect...

Or more aptly: of course skin effect is always a thing.  It's what you do about it that matters.  What makes you think common designs are fatally flawed in regards to this property?

Tim
« Last Edit: April 04, 2019, 06:36:56 pm by T3sl4co1l »
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 

Offline hagster

  • Frequent Contributor
  • **
  • Posts: 394
Re: How to fight over the skin effect on home made antennas ???
« Reply #7 on: April 04, 2019, 09:00:49 pm »
As others have said, unless you are paying a lot for your substrate, the dielectric losses will dominate.

For skin effect you can mitagate it by using wider tracks and a thicker substrate. Lots of antennas use an very thin PCB with an air gap over a ground plane.

Plating doesnt do much for microstrip tx lines as the current is flowing on the underside of the track not on the top surface. Also watch is doe ENIG as the nickel is ferromagnetic and lossy.

Personally I use normal solder resist to protect the surface from tarnishing over time.
 

Offline Wallace Gasiewicz

  • Super Contributor
  • ***
  • Posts: 1161
  • Country: us
Re: How to fight over the skin effect on home made antennas ???
« Reply #8 on: June 24, 2021, 10:54:22 pm »
As far as conductivity goes, copper is only beat by silver.
Aluminum is third but it has a greater skin depth at higher freq. So it is close to copper.
If you silver plate, it has to be thicker than one skin depth. I don't know how to do this with flat traces where the edges are the most conductive and hardest to plate. At GHz freq "skin effect" becomes "edge effect" with the RF concentrating at the edges of traces.
I dunno but maybe a round wire instead of a flat trace might be better?
I use silver plated craft jewelry wire for some connections because it solders like a dream, but I do not think the silver plate is thick enough to make a difference, maybe someone else knows the answer to this. Maybe at GHz freq the craft wire has enough silver plate to make a difference.

Maybe get a scrap piece of coax that has silver plated shield and use a strand (or two or three or..) of that if all you need is a thin wire? I am assuming you are using PCB trace for antenna. Again, I dunno, just some thoughts.
Connectors and coax are critical at GHz freq. Use good connectors and coax that are both rated higher than your intended freq.

Wally KC9INK
 

Offline T3sl4co1l

  • Super Contributor
  • ***
  • Posts: 21606
  • Country: us
  • Expert, Analog Electronics, PCB Layout, EMC
    • Seven Transistor Labs
Re: How to fight over the skin effect on home made antennas ???
« Reply #9 on: June 25, 2021, 03:29:47 am »
On PCBs, it doesn't make much difference at all, as the fields are largely within the board, i.e. the rough, oxidized, bonded surface is where most of the current flows.  If you're building micro/strip/line yourself, you can use fully plated materials of course.

Sharp corners do concentrate current more than round; you would prefer coax to stripline resonators for example.  But you might justify the increased insertion loss or reduced maximum Q by the ease of construction or manufacture, and so planar filters are very popular in commercial design.

Tim
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 

Online Bud

  • Super Contributor
  • ***
  • Posts: 6877
  • Country: ca
Re: How to fight over the skin effect on home made antennas ???
« Reply #10 on: June 25, 2021, 03:37:50 am »
Skin effect should be the least of your concerns.
Facebook-free life and Rigol-free shack.
 

Offline ahbushnell

  • Frequent Contributor
  • **
  • Posts: 734
  • Country: us
Re: How to fight over the skin effect on home made antennas ???
« Reply #11 on: July 03, 2021, 03:36:59 am »
There are PCB materials designed for this.  There is a company called Rogers That makes this material among others.  It's probably in your pocket in your cell phone. 

https://www.rogerscorp.com/advanced-connectivity-solutions

Andy
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf