thanks very much!
i can understand that electronic field decrease in the direction of propagation if the transmission line is not ideal,but what i can not understand is the relationship between the electric field and voltage.in my opinion,the electric field is always orthogonal to the direction of the propagation even if the amplitude decrease,so the voltage will not change along the direction of the progation. this only happens in low frequency of course.how to understand it from the view of electromagnetic?
thanks again!