Remove back lobe in ArraySynthesisExample.m

In the ArraySynthesisExample.m example code, I'm trying to remove the back lobe, but so far I can't.

First I set the "BackBaffled" property of the ULA to false.

Then, I make sure my plot covers the full -180:180 range of Azimuth values.

When I set the interference direction to -180 degrees, unfortunately it makes the entire beam go away.

thetaan = -180;           % interference direction

So, is there a way I can suppress the back lobe digitally? I want to make all of the power go forward, not backwards. Is this method even possible?

Thanks in advance!!

Answer 1

[Honglei Chen]

Hi Chris,

I'm not sure what you mean here but it seems that you are using an isotropic element. Therefore, the lobe is generated because of the array geometry and because of the symmetry of a ULA, the -180 degree lobe is the same as the 0 degree lobe. Hence, if you remove -180 degree lobe, it removes 0 degree lobe too. In reality, the antennas are unlikely to be isotropic so it back lobe is in general much smaller compared to the main lobe.

HTH

[Chris Jagielski]

Yes I would want to change the antenna element itself, as you mentioned.

However, even with changing the antenna, as you said the symmetry of the ULA will make the -180 degree lobe the same as the 0 degree lobe.

[Honglei Chen]

Yes, that is true. It is due to the symmetry caused by the array geometry. Fortunately for most real element, the backlobe is much weaker so we can live with it.