Em waves and magnetic field lines

[physics user1]

So i know that magnetic field lines are closed, in an electromagnetc wave how can be these lines closed? i cannot picture this in my head

 

[Drakkith]

I believe they look something like the following:

 

[physics user1]

Thanks @Drakkith

 

[cpxuvs]

I believe they look something like the following:

Is an antenna in the middle?

 

[Drakkith]

Is an antenna in the middle?

Yes there is. I believe that's the radiation pattern of a standard dipole antenna.