find the sidelobe level

greetings.,

i worked on my graph plotting the radiation pattern of an antenna array. so., could anyone help me about findin the amplitude of the first sidelobe?? please...

[bym]

can you post a picture of your graph?

[lucky yeggina]

sure i can., but the problem is that., since i used the variable to be random number., the graph changes....... for every simulation.

Answer 1

[Honglei Chen]

If you have Signal Processing Toolbox, you can use findpeaks function to find peaks. In your case, if you find two biggest peaks then the second one should be your first sidelobe. You can see if you have the license for Signal Processing Toolbox by running following command

>> ver

The findpeaks function has been shipping since R2007b. It also gets a major improvement during R2010a.

HTH

[lucky yeggina]

thnq so much

[lucky yeggina]

thnq so much

[Ibrahim Ibrahim]

really yur answer is so much helpful :)

[ibrahim ahmed]

I am sorry but I didn't understand can you ,Honglei Chen Explain for me please Because I'm a beginner

Answer 2

[bym]

you can use

diff()

to see where the slop of the amplitude changes sign