Still lower noise radio astronomy

SW but there are two ways of using an antenna at multiple
SW wavelengths. One is to use a diplexer ... The second method is to
SW put separate feed horns side by side. ...

In article ,
George Dishman writes:
The DSN approach is to amplify the whole S-band using
a wideband LNA, then digitise it, then extract the
sub-bands purely in the digital domain.

Sorry, I should have written "bands" instead of "wavelengths." Yes,
the whole S-band is observed digitally through a single feed horn and
LNA, but the question I was trying to answer is how to observe X and
K bands too. I'm pretty sure both approaches I mention are used at
various observatories, but I don't know which one the DSN chose.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
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