A wireless transmission system includes first and second transmission line couplers. The first transmission line coupler is arranged in an annular shape and formed of a pair of signal lines that transmit a differential signal. The second transmission line coupler is shorter than the first transmission line coupler and formed of a pair of signal lines that transmit a differential signal. The first and second transmission line couplers are arranged so that, if at least one of the first and second transmission line couplers rotates about a rotational axis and if one of the signal lines of the second transmission line coupler crosses a gap between the ends of one of the signal lines of the first transmission line coupler, the other signal line of the second transmission line coupler does not cross a gap between the ends of the other signal line of the first transmission line coupler.

Induction heating power supplies, data collection systems, and induction heating systems to communicate over an induction heating cable are disclosed. An example induction heating power supply includes a power conversion circuit configured to: convert input power into induction heating power and transmit the induction heating power via an induction heating cable, and at least one of a receiver circuit coupled to the induction heating cable and configured to receive data via the induction heating cable or a transmitter circuit coupled to the induction heating cable and configured to transmit data via the induction heating cable.

A wireless transmission system includes first and second transmission line couplers. The first transmission line coupler is arranged in an annular shape and formed of a pair of signal lines that transmit a differential signal. The second transmission line coupler is shorter than the first transmission line coupler and formed of a pair of signal lines that transmit a differential signal. The first and second transmission line couplers are arranged so that, if at least one of the first and second transmission line couplers rotates about a rotational axis and if one of the signal lines of the second transmission line coupler crosses a gap between the ends of one of the signal lines of the first transmission line coupler, the other signal line of the second transmission line coupler does not cross a gap between the ends of the other signal line of the first transmission line coupler.

There is described a network distribution system using common communication and power comprising a power line, multiple fire alarm units, and a power line control device. The power line provides alternating current, and the fire alarm units are coupled to the power line. The power line control device is coupled to the power line and a particular fire alarm unit of the plurality of fire alarm units. The power line control device comprises a communication translator to convert between power line and non-power line protocols and a power line core to modulate signals to, and demodulate signals from, the power line.

A communication system can include a first transceiver and a second transceiver that can communicate digital baseband data via a direct current (DC) power line bus in the wellbore. One or more of the transceivers includes a demodulator for demodulating the digital baseband data received from the DC power line bus into multiple digital data streams, and includes a digital processor for filtering and applying error correction to the digital data streams to produce a decoded digital data stream.

A communication system can include a first transceiver device and a second transceiver device that can communicate digital baseband data via a direct current (DC) power line bus in the wellbore. One or more of the transceivers includes a coupler for the DC power line bus for transceiving data via the DC power line bus with the other transceiver device, modulation circuitry, demodulation circuitry, and compensator circuitry. The compensator circuitry can be communicatively coupled to the coupler for providing an operating point to the coupler in response to both the modulation circuitry and the demodulation circuitry being in an idle state, to reduce effects of low frequency drift and noise in signals.

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.

A communication system can include a first transceiver device and a second transceiver device that can communicate digital baseband data via a direct current (DC) power line bus in the wellbore. One or more of the transceivers includes a coupler for the DC power line bus for transceiving data via the DC power line bus with the other transceiver device, modulation circuitry, demodulation circuitry, and compensator circuitry. The compensator circuitry can be communicatively coupled to the coupler for providing an operating point to the coupler in response to both the modulation circuitry and the demodulation circuitry being in an idle state, to reduce effects of low frequency drift and noise in signals.

Aspects of the subject disclosure may include, supplying an alternating voltage waveform to a winding coupled to a magnetic core of an inductive power supply to regulate an alternating magnetic flux in the magnetic core. The alternating voltage waveform can be generated by selectively enabling one or more switches coupled to a storage device. The subject disclosure may further include configuring the one or more switches according to a configuration during a portion of a period of the alternating voltage waveform, and measuring a characteristic of an alternating current flowing in a conductor coupled to the magnetic core during the portion of the period of the alternating voltage waveform. Other embodiments are disclosed.

Provided are a coupling device, a surface wave coupling method, and an open wire surface wave wireless coverage system. The coupling device comprises: a high-order mode direct coupling module configured to couple a first electromagnetic wave from a transmitter to form a second electromagnetic wave propagating in a preset high-order guided wave mode; a mode converting and filtering module configured to convert the second electromagnetic wave into a third electromagnetic wave propagating in a superposition of a plurality of guided wave modes, and to filter the high-order guided wave mode in the third electromagnetic wave to obtain a fourth electromagnetic wave propagating in the preset low-order guided wave mode; and a mode matching module configured to convert the fourth electromagnetic wave into a fifth electromagnetic wave propagating along a surface of an open wire in a target guided wave mode.