Open problems in Electromagnetics & Antennas ?

[atul_microwaves_antenna]

open problems in antennas

Hello All,
Dose any one know what are the current open problems in Electromagnetics & Antennas?
Some of the fields to openly do research which I know are MIMO,Smart Antennas,Active & passive antennas etc etc but still I am not very specifically know about it.Also I know that application of GA and ANN to old problems on optimization are also good thing,and I am considering this as open problem option.
In electromagnetics I know scaterring by solid surface is still open problem but not sure of it.
Dose anyone know few open problems which can be openly targeted?
Thanks in advance.

 

[Azulykit]

Antennas are always too big. Make them smaller, with more gain and efficiency. And by the way increase both beamwidth and gain simultaneously. I ma asked to do that every day.

They also have to cost less and have greater bandwidth.