Re: electroless nickel for low rf attenuation?

Gordon,

There are a number of other constraints.  Without going into the details,
electroless nickel is a strong candidate plating material, based on initial
results.  Since the electrical and magnetic properties of nickel-phosphorus
deposits vary with phosphorus content, I am interested if anyone has
detailed information on rf attenuation of this or a similar material.  The
resistivity of nickel-phosphorus increases linearly with phosphorus content,
but as the material approaches the "high-phosphorus" regime of 10% by weight
or higher, the material becomes non-ferromagnetic.  I note that the skin
depth is proportional to 1/sqrt(sigma*mu), where sigma is the electrical
conductivity and mu is the magnetic permeability.  I suppose one should
really consider these material parameters as functions of frequency f,
sigma(f) and mu(f).

Perhaps someone has encountered this or a similar problem before and could
provide some guidance.

Grant

"Gordon Couger" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
>
> "Grant Kiehne" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > Thanks for suggestions on other platings, but I am interested
specifically
> > in electroless nickel.  What type of electroless nickel is best for low
rf
> > attenuation?  --Grant
>
> Why are you married to eletcoless nickel when bare aluminum is probably a
> better choice? If corrosion is a serious  problem you have a lot of
problems
> and unless this is a very short lived item it will probably be less
> expensive to go with time proven solutions such a silver plated  stainless
> steel or copper flashed with gold.
>
> The coefficient of terminal expansion of aluminum is going to give you
fits
> with  the cavity tuning as well.
>
> Gordon
>
> Gordon Couger
> Stillwater, OK
> www.couger.com/gcouger
>
>