Mu wrote:

On Wed, 05 Nov 2003 17:41:54 +0100, Ralph Savelsberg
wrote:

And more in general stands for Active Electronically Scanned Array,
which is the name for the type of antenna/emitter group. Instead of a
mechanically swivelling antenna (with complicated waveguides and a heavy
hydraulic system to move it around) this has a flat, fixed array
consisting of multiple emitter/receiver modules. The beam is controlled
electronically and at least in theory such a radar can use multiple
modes simultaneously. In the F/A-18F (with the ACS) this could mean that
for instance the pilot would have an air-to-air mode selected, while the
NFO in the back could be using a ground-mapping mode at the same time.

Regards,
Ralph Savelsberg



Ave Ralph

Is this the phased array radar?
And if not,wthat's the difference?

Greetz Mu



Technically the AESA is an active phased array radar whilst older phased
array radars (like the `Flash Dance' in the MiG-31 or the APQ-164 fitted
to the B-1B) are so-called passive phased array radars.

The latter (passive) has a single transmitter/receiver and somehow
applies a phase shift to the signals sent to various parts of the
antenna, depending on the location on the antenna, whilst the former
actually uses a large number of transmitter/receiver units that each
operate at a different phase and possibly in a different mode.
In both cases the `beam' is sent in a certain direction through
adjusting the phase across the antenna, enabling a far higher scan rate,
but the actively scanned array can actually generate multiple beams as
well.

I don't know the intricacies. Harry Andreas will probably be able to
give a much more detailed answer than I can.

Regards,
Ralph Savelsberg