Degrees of a change in an insertion loss of a main line and a change in a phase of a signal are small regardless of whether or not detection is performed by using a sub-line. A directional coupler includes a main line, a sub-line, a first termination circuit, a second termination circuit, and a switch. The sub-line has a first end and a second end. The first termination circuit terminates the first end and the second end of the sub-line. The switch switches connection and disconnection between the sub-line and the first termination circuit.

A directional coupler utilizes an inductive element of a power amplifier and a coupled conductive element. The inductive element of the power amplifier is a functioning element within the power amplifier and at least part of the inductive element of the power amplifier is disposed in a multi-layer substrate. At least part of the coupled conductive element is disposed in the multi-layer substrate. The coupled conductive element is configured to be inductively coupled to the inductive element of the power amplifier such that the coupled conductive element carries a first RF signal that is representative of a second RF signal within the inductive element of the power amplifier.

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.

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 dielectric waveguide comprising a dielectric probe at each end, wherein the dielectric probes are arranged to transfer energy.

A system that incorporates teachings of the present disclosure may include, for example, a matching network including a tunable reactance circuit configured to be coupled to at least one of a transmitter portion and a receiver portion of a communication device, wherein the tunable reactance circuit is adjustable to a plurality of tuning states, and wherein the determination of a tuning state is based on parameters associated with a detected interference. Additional embodiments are disclosed.

An electronic circuit assembly comprising: i) a circuit card assembly (CCA) having circuits integrated on a circuit surface; ii) a housing having an upper surface and a lower surface disposed on the CCA circuit surface, the housing comprising a via extending from the lower surface to the upper surface; and iii) a waveguide assembly disposed in the via. The waveguide assembly comprises: a) a first waveguide having a first dielectric value, a contact end of the first waveguide configured to make contact with the CCA circuit surface; b) a second waveguide having a second dielectric value, wherein the first dielectric value is greater than the second dielectric value; and c) a carrier for holding the first waveguide in contact with the second waveguide. The electronic circuit assembly further comprises: iv) a wave washer disposed in the via on a support surface of the carrier; and v) a third waveguide having a third dielectric value that is less than the second dielectric value. The third waveguide is disposed in the via between an end of the second waveguide and the upper surface of the housing. The wave washer presses apart the third waveguide and the waveguide assembly such that the contact end of the first waveguide is pressed into contact with the CCA circuit surface and the third waveguide is pressed into contact with an external circuit disposed above the housing.

An annual directional coupler having at least three taps, which are each arranged relative to one another around routes having a wavelength difference of of a wave guide wavelength, includes in particular at least two branch lines, wherein a first branch line has at least three taps and wherein the at least second branch line does not have any taps and is supplemented by an additional route corresponding to the wave guide wavelength.

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.

A method for coupling dielectric waveguide cables is disclosed. The method comprises positioning a first dielectric waveguide cable and a second dielectric waveguide cable such that a first segment of the first dielectric waveguide cable and a second segment of the second dielectric waveguide cable are disposed side by side, generating an electromagnetic coupling between the first segment and the second segment, and transmitting an electromagnetic wave signal from the first dielectric waveguide cable to the second dielectric waveguide cable through the electromagnetic coupling.