On 8/30/07 4:31 PM, in article ,
"Tam/WB2TT" wrote:


"Dave Platt" wrote in message
...
What is the highest radio frequency used for astronomy? Is it 3,438
GHz?

According to the link below, it is 3,438 GHz:

http://books.nap.edu/openbook.php?re...=11719&page=11

Is 3,438 GHz the highest radio frequency used for astronomy?

That's very much a matter of convention. It all depends what you
choose to call "radio frequency" and what you choose to call something
else.

As the article you cite points out, the measurements at 3438 GHz
(3.438 THz) blur the lines between microwave measurements (which many
would call "radio") and far-infrared measurements (which may would not
call "radio frequency").

One source I see gives a frequency of 3.0 THz as the boundary between
"microwave" and "infrared". That boundary point is, I believe,
entirely one of human convention - there's no magical change in the
behavior of the signals as you cross from one side of this frequency
to the other.

If you choose to treat the conventional boundary point of 3.0 THz as
being significant for the purpose of your question, then one would
have to say that the 3,438 GHz measurements you refer to are *not*
"radio frequency" measurements, but rather "far-infrared"
measurements.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

I am curious here. At some point you have to switch from metallic conductors
and antennas to lenses and other optics. Any idea what the highest frequency
RF amplifier works at?

Tam



It's all subject to state-of-the-art. 50 years ago 300 MHz. was complex to
work with and 10 GHz. was considered way out there. Today 300 MHz is about
as simple as DC and 10 GHz. is fairly straightforward to work with.

I imagine that in another 50 years or less, Integrated hybrid circuits for 3
THz. will be on the shelf items for experimenters to play with.