Aspects of the subject disclosure may include, for example, a coupling module that includes a waveguide that guides a first electromagnetic wave conveying data from a transmitting device. A dielectric coupler receives the first electromagnetic wave from the waveguide to form a second electromagnetic wave, and that guides the second electromagnetic wave along the dielectric coupler adjacent to a transmission medium, and wherein the dielectric coupler has a length that supports a cancellation of at least one cancelled wave mode from a coupling of the second electromagnetic wave to the transmission medium.

A directional coupler includes: a first waffle-iron ridge waveguide extending from one end to other end; a second waffle-iron ridge waveguide extending from one end to the other end; a first bypass waveguide connecting a first site of the first waffle-iron ridge waveguide and a first site of the second waffle-iron ridge waveguide; and a second bypass waveguide connecting a second site of the first waffle-iron ridge waveguide and a second site of the second waffle-iron ridge waveguide.

In accordance with one or more embodiments, a directional coupler includes a first dielectric cable is configured to receive a first electromagnetic wave from the first port and to generate a second electromagnetic wave that propagates along a transmission medium in a first direction without requiring an electrical return path. A second dielectric cable is configured to couple a first portion of the second electromagnetic wave to a second port, wherein a second portion of the second electromagnetic wave continues to propagate in the first direction along the transmission medium. A third dielectric cable is configured to couple the second portion of the second electromagnetic wave to a third port and to isolate the third port from a third electromagnetic wave propagating along the transmission medium in a second direction that is opposite to the first direction.

Aspects of the subject disclosure may include, a system having a polyrod antenna array. Beam steering can be performed according to a first subset of elements of the polyrod antenna array generating first electromagnetic waves with a first phase that is different from a second phase of the first electromagnetic waves being generated by a second subset of elements of the polyrod antenna array. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a transmission device that includes a first coupler that guides a first electromagnetic wave to a first junction to form a second electromagnetic wave that is guided to propagate along the outer surface of the transmission medium via one or more guided-wave modes. These mode(s) have an envelope that varies as a function of angular deviation and/or longitudinal displacement. Other embodiments are disclosed.

Aspects of the subject disclosure may include, a system having an absorber and a coupling device. The absorber includes absorbent material that absorbs radiation. The coupling device is positioned in and surrounded by the absorber. The coupling device facilitates transmitting or receiving of an electromagnetic wave along a transmission medium, where the electromagnetic wave propagates along the transmission medium without requiring an electrical return path. Other embodiments are disclosed.

A directional coupler includes a first main line, a second main line, first sub-lines, second sub-lines, a first output terminal, a second output terminal, a first inductor, and a second inductor. The first output terminal is configured to be coupled to the first sub-lines. The first output terminal is configured to output a first detection signal corresponding to a first radio-frequency signal transferred through the first main line. The second output terminal is configured to be coupled to the second sub-lines. The second output terminal is configured to output a second detection signal corresponding to a second radio-frequency signal transferred through the second main line. The first inductor is provided in a first signal path including the first output terminal. The second inductor is provided in a second signal path including the second output terminal.

A refractive index n of a dielectric material is larger than a refractive index of the outside in a lateral direction X and/or a vertical direction Y perpendicular to an electromagnetic wave travelling direction Z, the inside of a waveguide-path has slow electromagnetic wave propagation velocity, compared to an area on the outside, the maximum dimension in the lateral direction and/or the vertical direction of the waveguide-path has a dimension which is specified by a formula below. The formula is: tan(k.sub.sa/2)=k.sub.f/k.sub.s, or tan(k.sub.sa/2)=k.sub.s/k.sub.f. Here, k.sub.s: propagation constant of an electromagnetic wave low-speed area, k.sub.f: propagation constant of an electromagnetic wave high-speed area, and a: maximum dimension in the X direction and/or the Y direction of the waveguide-path.

In accordance with one or more embodiments, a dielectric coupler includes a neck portion configured to receive a first electromagnetic wave from a hollow waveguide. A flared portion is configured to generate, responsive to the first electromagnetic wave, a second electromagnetic wave along a surface of a transmission medium, wherein the flared portion at least partially surrounds the transmission medium, wherein the second electromagnetic wave propagates along the surface of the transmission medium without requiring an electrical return path. A tapered portion is configured to interface the neck portion to the flared portion.

Aspects of the subject disclosure may include, a system having an absorber and a coupling device. The absorber includes absorbent material that absorbs radiation. The coupling device is positioned in and surrounded by the absorber. The coupling device facilitates transmitting or receiving of an electromagnetic wave along a transmission medium, where the electromagnetic wave propagates along the transmission medium without requiring an electrical return path. Other embodiments are disclosed.