hello, Actually I looking for Polyurethane made RF Absorber. Do you have any Idea how to impregnate carbon into Polyurethane foam.

 

http://www.g3rfl.co.uk/absorb.htm

 

thank you but i need to make carbon impregnated absorber. Do you have any idea how to make it

 

they are a lot more difficult than you might think.
first the easy part, getting the carbon into a matrix approximating a foam,

second comes the fun part,
if the matching between the ambient and the foam has a high VSWR, then you are just going to get a reflection.

The need is to provide a graduated match,
either by machining the shape or by selective material deposition,

As for how a DIY solution, seems to be a few on the web, but not done it personally,

Thoughts off top of head,
graphite / charcoal mixture in an epoxy, how about layers getting lighter as the layers get near the surface ?

I also wonder, what does carbon fibre sheet look like at RF ?
you can get that in different "densities"

Let us know how your experiments get on.

 

they are a lot more difficult than you might think.
first the easy part, getting the carbon into a matrix approximating a foam,

second comes the fun part,
if the matching between the ambient and the foam has a high VSWR, then you are just going to get a reflection.

The need is to provide a graduated match,
either by machining the shape or by selective material deposition,

As for how a DIY solution, seems to be a few on the web, but not done it personally,

Thoughts off top of head,
graphite / charcoal mixture in an epoxy, how about layers getting lighter as the layers get near the surface ?

I also wonder, what does carbon fibre sheet look like at RF ?
you can get that in different "densities"

Let us know how your experiments get on.

thanks andrew let me try with carbon black and epoxy I will let you know the results