From: firstname.lastname@example.org (carltons)
Subject: Re: dBm and Microvolt/meter
References: <3D971DF6.email@example.com> <firstname.lastname@example.org>
User-Agent: NewsWatcher-X 2.2.3b2
NNTP-Posting-Date: Wed, 09 Oct 2002 08:43:14 GMT
Date: Wed, 09 Oct 2002 08:43:14 GMT
In article , Jim Thompson
> On 8 Oct 2002 17:22:06 -0700,
> email@example.com (Dale Chisholm),
> In Newsgroup: sci.electronics.design,
> Article: ,
> Entitled: "Re: dBm and Microvolt/meter",
> Wrote the following:
> |Jim Thompson wrote in message
> |> On Tue, 08 Oct 2002 08:44:53 -0700,
> |> Jim Weir ,
> |> In Newsgroup: sci.electronics.design,
> |> Article: ,
> |> Entitled: "Re: dBm and Microvolt/meter",
> |> Wrote the following:
> |> |With all due respects, Jim, the relationship between dBm and µV/m is
> |> |and antenna factors at the goesinta and goesouta..
> |> |
> |> |Jim
> |> |
> |> |Jim Thompson
> |> |shared these priceless pearls of wisdom:
> |> |
> |> |->
> |> |->Eh? There is NO relationship between dBm and uV/meter.
> |> Write the equation ;-)
> |> WITHOUT OTHER FACTORS BEING SPECIFIED there is NO relationship.
> |> ...Jim Thompson
> |Is it REALLY so obscure that you can't give the guy some more
> |definitive help?
> I was just trying to stress that there's no pat equation relating uV/m
> to dBm. As you pointed out there's antenna area and efficiency into a
> specified load before you can make the equivalency.
> ...Jim Thompson
I agree with Jim and the complicated calculation of power coming out of
the antenna of given aperature and all, but no one mentions the fact that
uV/M is not just field strength, but the Electrical field strength. I
know. Picky, picky. Anyone want to calculate the Poynting vector value?