Apparatus and methods for launching electromagnetic waves having a certain electric field structure

A method, comprising:

• launching, by a transmitter, an electromagnetic wave having a wavefront configuration, wherein the electromagnetic wave propagates along a transmission medium without requiring an electrical return path toward a structure;
• and
• adjusting, by the structure, the wavefront configuration to generate an adjusted wavefront configuration of the electromagnetic wave that propagates along the transmission medium away from the structure, the adjusted wavefront configuration having a phase delay profile that is dependent on an azimuth angle around an axis of the structure.

A device, comprising:

• means for receiving a signal;
• and
• means for launching, according to the signal, an electromagnetic wave along a transmission medium, wherein the electromagnetic wave propagates along the transmission medium without requiring an electrical return path, and wherein the electromagnetic wave has a phase delay profile that is dependent on an azimuth angle around an axis of the transmission medium.