# How to mitigate the effect of side lobes of smart antenna?

Hi Experts.
In terms of RF Design, how do we mitigate the effect of side lobes of smart antenna? In 5G.
Could we eliminate totally side lobes omited from antenna?
As side lobes considered as interference.

Side lobes means unwanted radiation in undesired directions, and it is generally desirable to minimize the sidelobe level (SLL), which is measured in decibels relative to the peak of the main beam.

If they are too high it can cause interference in an adjacent whilst also being susceptible to interference from adjacent links.

No! Side lobes cannot be completely removed.
They can be reduced by really good and expensive RF filters but not possible to remove them. Mathematics doesnâ€™t allow that.
Remember Fourier transforms!

1 Like

I understand.
You mean by Fourier transforms because it has multiple coefficcient which will generate side lobes.
My confusion is why at anntena center we have like longer/wide beam that has almost all power in that main lobe?
In otherwords why main lobe always found at central of the anntena mathmatically we could say maximal power found on the straight sight line of the anntena where main lobe found?

Side lobes in smart antenna are at least 15 dB under main lobe!
Nobody is concerned about side lobes!

Understand. Thanks.
But if they found then it will generate interferences no?
About main lobe â€¦any idea why its always found on smart antenna center?

And 15 dB is considered high, no?

Main lobe can be steered in any direction with 105 degrees H and 30 degrees V.
Side lobes generate little interference due to 15 dB difference from main beam.

Appreciated.
About side lobes that has power of 15 db; doesnâ€™t 15 db amount considered high amount?
What limit of power considered as high in telecommunication generally? 30 dB + ?

Just trying to understand if that value 15 db considered high amount of power or not.

That amount of power is not much and is an output, side effect, of beamforming.

You confuse power with attenuation. 15 dB is attenuation of side lobe from main lobe!

Ah now makes more sense. Thanks again.

So if main lobe is 50 dB for instance â€¦then side lobe would be around 35 dB?
(15 dB attenuated)

Main lobe is evaluated by SSB RSRP in dBm not dB.
Power is measured in watts or dBm not in dB!

I understand. Sorryâ€¦letâ€™s forget from word â€śpowerâ€ť.

If I have main lobe with 50 dB so side lobe would be attenuated by 15 dB from main lobe, so side lobe would be around 35 dB, is it?