A directional coupler includes a main line, sub lines, and a multilayer substrate. The multilayer substrate includes dielectric layers. The multilayer substrate has a first and a second principal surface. The main line, the first, second, and third sub lines are each formed in a looped shape in plan view from a thickness direction of the multilayer substrate, and are provided to different dielectric layers among the dielectric layers. The first, second, and third sub lines have first distances different from each other. Among the first, second sub line, and third sub lines, the longest sub line having the longest first distance and the shortest sub line having the shortest first distance are disposed on the first principal surface of the main line, and the intermediate sub line having the intermediate first distance is disposed on the second principal surface of the main line.

A combiner/divider includes a plurality of input/output waveguides distributed in a plane and diverging in at least a partially common direction away from a central point. Each input/output waveguide extends from an outer node disposed distal of the central point to an inner port proximate to and spaced from the central point. Each input/output waveguide has a respective dimension in the plane that increases between the inner port and the outer node. An output/input waveguide has an aggregate port proximate to the central point and facing the inner ports. A transition waveguide defines an open cavity that flares outwardly in the plane from the aggregate port toward the inner ports and communicatively couples the output/input waveguide with the input/output waveguides. Opposing distal surfaces of the transition waveguide and inner port edges are spaced apart by a distance that decreases with increasing distance from the aggregate port.

A signal transmission system including: a first connector apparatus, and a second connector apparatus that is coupled with the first connector apparatus. The first connector apparatus and the second connector apparatus are coupled together to form an electromagnetic field coupling unit, and a transmission object signal is converted into a radio signal, which is then transmitted through the electromagnetic field coupling unit, between the first connector apparatus and the second connector apparatus.

Electromagnetic coupler systems including built-in frequency detection, and modules and devices including such. One example of an electromagnetic coupler system include an electromagnetic coupler having an input port, an output port, a coupled port, and an isolation port, the electromagnetic coupler including a main line extending between the input port and the output port, and a coupled line extending between the coupled port and the isolation port, the electromagnetic coupler being configured to produce a coupled signal at the coupled port responsive to receiving an input signal at the input port. An adjustable termination impedance is connected to the isolation port. A frequency detector is connected to the adjustable termination impedance and to the coupled port, and configured to detect a frequency of the coupled signal and provide an impedance control signal to tune the adjustable termination impedance based on the frequency of the coupled signal.

In accordance with one or more embodiments, a transceiver is configured to generate a first signal in response to receiving a first guided electromagnetic wave from a remote system via a launcher. A controller is configured to generate a channel quality indicator in response to the first signal. The transceiver is further configured to generate a second signal that conveys the channel quality indicator. The launcher, responsive to the second signal, is further configured to launch a second guided electromagnetic wave that conveys the channel quality indicator to the remote system, wherein the second guided electromagnetic wave is guided by the transmission medium and propagates along the transmission medium.

In accordance with one or more embodiments, a transceiver is configured to generate a first signal in response to receiving a first guided electromagnetic wave from a remote system via a launcher. A controller is configured to generate a channel quality indicator in response to the first signal. The transceiver is further configured to generate a second signal that conveys the channel quality indicator. The launcher, responsive to the second signal, is further configured to launch a second guided electromagnetic wave that conveys the channel quality indicator to the remote system, wherein the second guided electromagnetic wave is guided by the transmission medium and propagates along the transmission medium.

A directional coupler includes a multilayer body, a conductor (31), and a conductor (32). The conductor (31) is a conductor that is arranged in an insulating layer (21) of the multilayer body and that extends in a certain shape. The conductor (32) is arranged on a side of an insulating layer (22) of the multilayer body opposite the insulating layer (21). The conductor (32) runs parallel to the conductor (31) and is electromagnetically coupled to the conductor (31). The conductor (32) has a winding shape with one or more rounds, and has a conductor portion (321) and a conductor portion (325) that are arranged adjacent to each other with a spacing in a direction orthogonal to a running parallel direction. In plan view of the multilayer body, the conductor (31) is arranged between the conductor portion (321) and the conductor portion (325).

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.

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 coupler having a controller device; and a plurality of conductive members that each have a distal end, a proximal end, and a curved shape. Each of the plurality of conductive members can have an opening through a surface thereof, and each of the plurality of conductive members can be connected to the controller device. The distal end of each of the plurality of conductive members can be farther away from an outer surface of a transmission medium than the proximal end, and a width of each of the plurality of conductive members can increase in a direction from the proximal end to the distal end. The controller device can facilitate transmission of signals via the plurality of conductive members, and the signals can induce electromagnetic waves that propagate along the transmission medium without requiring an electrical return path. Other embodiments are disclosed.