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, receiving a signal, and launching, according to the signal, an electromagnetic wave along a transmission medium, where the electromagnetic wave propagates along the transmission medium without requiring an electrical return path, and where the electromagnetic wave has a phase delay profile that is dependent on an azimuth angle about an axis of the transmission medium. Other embodiments are disclosed.

A quasi-optical coupling system launches and extracts surface wave communication transmissions from a wire. At millimeter-wave frequencies, where the wavelength is small compared to the macroscopic size of the equipment, the millimeter-wave transmissions can be transported from one place to another and diverted via lenses and reflectors, much like visible light. Transmitters and receivers can be positioned near telephone and power lines and reflectors placed on or near the cables can reflect transmissions onto or off of the cables. The lenses on the transmitters are focused, and the reflectors positioned such that the reflected transmissions are guided waves on the surface of the cables. The reflectors can be polarization sensitive, where one or more of a set of guided wave modes can be reflected off the wire based on the polarization of the guided wave modes and polarization and orientation of the reflector.

The present invention involves utilizing AC power lines adapted for connection to an AC power source and a signal line to perform baseband signal transmission and communication. According to the invention, a threshold voltage is provided as a comparison reference for an AC input voltage to determine whether the communication is permitted. If the AC input voltage is greater than the threshold voltage, the communication is permitted. On the contrary, if the AC input voltage is smaller than the threshold voltage, the communication is not permitted. By virtue of the invention, the initiation time and the termination time of the baseband signal communication for each load tend to be substantially identical. Reliability is thus increased and noise interference problem is not created.

Embodiments of this application disclose a method, an apparatus, and a system for information transmission in a PLC network. A switch control apparatus in embodiments of this application includes a switch and a coupling circuit. The coupling circuit is connected in parallel to two ends of the switch. When the switch is open, the coupling circuit transmits a first power line communication (PLC) signal to a gateway device. In embodiments of this application, when the switch is open, the PLC signal may be sent to the gateway device and information such as power off and tripping may be reported to the gateway device.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit connected between the first and second terminals includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.

Aspects of the subject disclosure may include, receiving a signal, and launching, according to the signal, an electromagnetic wave along a transmission medium, where the electromagnetic wave propagates along the transmission medium without requiring an electrical return path, and where the electromagnetic wave has a phase delay profile that is dependent on an azimuth angle about an axis of the transmission medium. Other embodiments are disclosed.

A well tool for use in a wellbore can include a motor for performing a well operation. The well tool can include a switch that is couplable between the motor and a wireline. The switch can be toggleable between (i) a first operational state for providing the power to the motor by coupling the motor to an external power source and (ii) a second operational state for decoupling the motor from the external power source. The well tool can include a motor controller coupled to the switch for toggling the switch between the first operational state and the second operational state in an arrangement configured to impart, on the wireline, multiple current pulses including data encoded in the current pulses according to an encoding scheme.

The present application is concerned with a system for transmitting and/or receiving the control and sensing signals between the control units and the power electronic components. One system according to the present application comprises: a transceiver adapted to modulate the communication signal on a communication signal frequency band, and a coupler connected to the power conductor and adapted to couple the modulated communication signal to the power conductor. The present application also concerns a method for transmitting and receiving the control and sensing signals.

Provided are a power carrier signal coupling circuit and a communication system. The power carrier signal coupling circuit includes a first power carrier signal coupling channel and a second power carrier signal coupling channel. A phase of a three-phase alternating current (AC) power line serves as a common channel, the first power carrier signal coupling channel is arranged between the common channel and one of two phases of the three-phase AC power line other than the phase of the three-phase AC power line serving as the common channel; and the second power carrier signal coupling channel is arranged between the common channel and the other of the two phases of the three-phase AC power line other than the phase of the three-phase AC power line serving as the common channel.