# Radiation patterns



## schmidty99 (Apr 5, 2011)

This problem is asking for the the current distribution that would give the radiation pattern shown. Sorry, I can't post the picture of the problem, but I was wondering if anyone had any info on how to deal with something like this. I can't find anything in my books and the internet isn't giving me and good answers, as far as I can tell anyway. Anything relating to radiation patters would help. Thanks!!

Tick tock!!!

I should add the radiation pattern is centered along a length of wire. Of which the wire is centered at the x, y, and z axis'.


----------



## CincinnatiControlsGuy (Apr 6, 2011)

This is why I recommend bringing along the ARRL handbook and AS MANY radiation patterns as you can find. There are no good references and the problems in the NCEES book just say, "Oh, it's intuitively obvious that it's B". FWIW, there is no way that you'll have to analyze an antenna problem so as to find closed form solutions; that would involve Gauss' law and some fairly esoteric Calculus. I realize this isn't an answer, but I freaked out about these problems at about the same point. However, the exam didn't contain that many RF problems and they weren't as nefarious as some of the NCEES practice problems. That said, I'd be curious to see what others think. It would be nice to see a general approach to these problems.


----------



## Jonjo (Apr 6, 2011)

schmidty99 said:


> This problem is asking for the the current distribution that would give the radiation pattern shown. Sorry, I can't post the picture of the problem, but I was wondering if anyone had any info on how to deal with something like this. I can't find anything in my books and the internet isn't giving me and good answers, as far as I can tell anyway. Anything relating to radiation patters would help. Thanks!!
> Tick tock!!!
> 
> I should add the radiation pattern is centered along a length of wire. Of which the wire is centered at the x, y, and z axis'.





I am at work and don't have the book with me , but I can tell because they asking for a current distribution the final equation for the distribution will be after you apply and play around with the 2nd Maxwell equation and / or the four Maxwell equation , I will be looking about this problem and try to solve and I get back to you, another book you can look at this problems is Shawm Mc Graw Hill "Electromagnetics", ship and very helpful with this chapters .


----------



## schmidty99 (Apr 6, 2011)

I agree GB. I'm not panicking about this type of problem, its just that I can't find a good answer, examples, etc. I have an engineering electromagnetics book as well as the ARRL, but they hardly touch it.

Jonjo: I'll be looking for anything you have to offer.

Thanks guys!!


----------



## Jonjo (Apr 6, 2011)

schmidty99 said:


> I agree GB. I'm not panicking about this type of problem, its just that I can't find a good answer, examples, etc. I have an engineering electromagnetics book as well as the ARRL, but they hardly touch it.
> Jonjo: I'll be looking for anything you have to offer.
> 
> Thanks guys!!



schmidty99

Did you look at Wikipedia as " current distribution that would give the radiation pattern " , there are 4 equation offer the distributions over the axes ( cylindrical coordinates ) .

Sorry , when I first read your question, I though associated with applying magnetics laws currently use on Electricity, but , when you talking about antenas all those formulas have to be deducted and that is not my field, I am on power field.

But still thinking take a look on Shawm Mc Graw Hill book series " Electromagnetics " , I will go home and going to take a look at it , If I find somethig I will let you know .

Good luck !!, I hope you pass this exam , relax , and do not nothing different then you just to before the exam , I guess you go for electronics ?

Jonjo


----------



## schmidty99 (Apr 7, 2011)

I hit Wikipedia but didn't come with anything similar, not that I could make heads or tails of. I'll be on again in the morning, heading to Madison in the afternoon. If you can find something, I'd be happy to take a look at it. Good luck everyone, and thanks for all your help, especially GroesbeckEE. Thanks again!!


----------



## Jonjo (Apr 7, 2011)

schmidty99 said:


> I hit Wikipedia but didn't come with anything similar, not that I could make heads or tails of. I'll be on again in the morning, heading to Madison in the afternoon. If you can find something, I'd be happy to take a look at it. Good luck everyone, and thanks for all your help, especially GroesbeckEE. Thanks again!!


http://en.wikipedia.org/wiki/Dipole_antenna

The four equation I mentioned in spherical coordinates


----------



## schmidty99 (Apr 7, 2011)

Thanks to everyone for there help! I'm as about as prepared as I'm ever going to be! We'll see ya on the flip side!


----------

