US Patent 10468739 Methods and apparatus for adjusting a wavelength electromagnetic waves

Aspects of the subject disclosure may include, generating, a first hollow waveguide that facilitates coupling, via the first dielectric coupler, a first electromagnetic wave onto a transmission medium, and a second hollow waveguide that facilitates coupling, via the second dielectric coupler, a second electromagnetic wave onto the transmission medium, where the first electromagnetic wave and the second electromagnetic wave combine to form a combined electromagnetic wave that propagates along the transmission medium without requiring an electrical return path, and where the first dielectric coupler has an adjustable length that facilitates an adjustment of a wave mode of the combined electromagnetic wave. Other embodiments are disclosed.