A data transmission system includes a first circuit, a second circuit, and a reference voltage generation circuit. The first circuit includes a transmitter powered by a first power supply voltage and having an input for receiving a data output signal, and an output. The second circuit includes a receiver powered by a second power supply voltage and having a first input coupled to the output of the transmitter, a second input for receiving a reference voltage, and an output for providing a data input signal. The reference voltage generation circuit forms the reference voltage by mixing a first signal generated by the first circuit based on the first power supply voltage and a second signal generated by the second circuit based on the second power supply voltage.

A data transmission system includes a first circuit, a second circuit, and a reference voltage generation circuit. The first circuit includes a transmitter powered by a first power supply voltage and having an input for receiving a data output signal, and an output. The second circuit includes a receiver powered by a second power supply voltage and having a first input coupled to the output of the transmitter, a second input for receiving a reference voltage, and an output for providing a data input signal. The reference voltage generation circuit forms the reference voltage by mixing a first signal generated by the first circuit based on the first power supply voltage and a second signal generated by the second circuit based on the second power supply voltage.

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.

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.

Aspects of the subject disclosure may include, for example, a transmission system having a coupling device, a bypass circuit, a memory and a processor. The coupling device can facilitate transmission or reception of electromagnetic waves that propagate along a surface of a transmission medium. The memory can store instructions, which when executed by the processor, causes the processor to perform operations including restarting a timer to prevent the bypass circuit from disabling the transmission or reception of electromagnetic waves by the coupling device. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a transmission system having a coupling device, a bypass circuit, a memory and a processor. The coupling device can facilitate transmission or reception of electromagnetic waves that propagate along a surface of a transmission medium. The memory can store instructions, which when executed by the processor, causes the processor to perform operations including restarting a timer to prevent the bypass circuit from disabling the transmission or reception of electromagnetic waves by the coupling device. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a system that performs operations including detecting a signal degradation of electromagnetic waves guided by a transmission medium, and adjusting at least one phase of signal components of the electromagnetic waves to produce adjusted electromagnetic waves having a hybrid wave mode and a non-optical frequency range to mitigate the signal degradation. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a system that performs operations including detecting a signal degradation of electromagnetic waves guided by a transmission medium, and adjusting at least one phase of signal components of the electromagnetic waves to produce adjusted electromagnetic waves having a hybrid wave mode and a non-optical frequency range to mitigate the signal degradation. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a node device includes an interface configured to receive first signals. A plurality of coupling devices are configured to launch the first signals on a transmission medium as a plurality of first guided electromagnetic waves at corresponding plurality of non-optical carrier frequencies, wherein the plurality of first guided electromagnetic waves are bound to a physical structure of the transmission medium. Other embodiments are disclosed.

A radiofrequency (RF) wireline communications system includes an interference filter for filtering interference noise at a cable interface that couples a cable of the system to functional circuitry. The interference filter includes a first termination resistance element coupled between a first cable conductor and a system ground, and a first termination reactance element coupled to the first termination resistance element. The first termination reactance element has a first termination reactance value selected to direct signals on the first cable conductor, having predetermined frequency characteristics, away from the system ground, and the first termination resistance element has a first termination resistance value selected as a pull-down resistance for interference signals having other than the predetermined frequency characteristics, that are not directed by the first termination reactance element away from the system ground, to cause the interference signals, having other than the predetermined frequency characteristics, to propagate to the system ground.