Aspects of the subject disclosure may include, for example, a system having a first plurality of transmitters for launching according to a signal, first electromagnetic waves, and a second plurality of transmitters for launching, according to the signal, second electromagnetic waves. The first electromagnetic waves and the second electromagnetic waves combine at an interface of a transmission medium to induce a propagation of a third electromagnetic wave, the third electromagnetic wave having a non-fundamental wave mode and a non-optical operating frequency, and wherein the second plurality of transmitters are spaced apart from the first plurality of transmitters in a direction of propagation of the third electromagnetic wave. Other embodiments are disclosed.