The radar aerial

[akafrank07]

Could anyone explain the concepts of the radar aerial for example;
"The systems most commonly used consist of either a wave-guide horn with a parabolic dish or a flat plate phased array system. Both systems are designed to focus the radiated energy into a narrow beam.
The radar pulses go through the wave-guide horn and reflect from the parabolic dish. This acts very much as the reflector in a light source (e.g. torch or landing light)."

I can't really make sense of this matter what research i do, could someone simplify this?
Cheers

[mad_jock]

I can't really make sense of this matter what research i do

You and 99.9 % of the country.

To really understand whats going on you need a degree in engineering or physics so I wouldn't worry about it.

They have a source of radar wigglie things which is surrounded by a "thing" which bounces them all towards the same point which lets them escape.

They then in there bid for freedom bounce down a tube which is highly technical in its design to arrive where they are useful. They are then squirted towards another thing which directs them in a direction that you want.

Any use?

[darkbarly]

To the observer, wave guides are like river banks, guiding the waves(ripples) towards a destination(harbour). If not impeded, the pulses spread out and disperse. When the tide reverses(radar returns), only specially shaped parabolic dishes(harbours) can direct ripples back up the river for assessment by the observer(receiver).

Kinks and turns in the river bank create disturbances in the wave patterns and create noise. Any noise can be mis interpreted by the observer so its best avoided.

ONE BIG WAVE, accelerating towards you is something else altogether;)

[paco]

The generated pulses travel from the transmitter to the reflector (via the duplexer) through either coaxial cable or a hollow, generally rectangular, metal tube called a wave guide, which prevents excessive power loss. The RF energy is injected into the waveguide by a probe, which is simply an antenna that only radiates into the waveguide.

The phased array system uses slots in the flat plate to act as waveguides.

Suggest you google "waveguide image" to get a picture.

[akafrank07]

Thanks for your help guys :-)

[sevenstrokeroll]

first off , call it a radar ANTENNA...an aerial is a very old term that really does not describe a modern antenna.
even marconi use a large spaghetti bowl shapped device to concentrate radio waves both for transmission and reception.

radar is not that hard to understand...but it is important to know that at certain frequencies (wavelengths if you are thinking aerials) a radio wave can't just follow a wire, but it is directed by a horn or a wave guide (pipe)

go out and look at an air traffic control radar installation...it should be painted orange and spin around and around. don't look at pictures of the home system of england during WW2...its different a little bit now.

phased array antennas are non moving, some smart guy figured out how to do it without moving parts.