The present invention relates to a data cable. An embodiment of the data cable comprises at least one wire pair and an internal element. The at least one wire pair has two wires running parallel in the longitudinal direction of the data cable. The internal element has at least one flat section. The at least one wire pair and the internal element are arranged in the data cable in such a way that the at least one wire pair lies against the at least one flat section of the internal element.

A device for deciding characteristics of a differential signal cable at a transmission rate of not less than 10 G baud includes a selector switch that changes a transmission rate or an output power of a test signal to be supplied to the differential signal cable, a signal transmitting circuit that generates a test signal at a different transmission rate or output power as one of the predetermined number of plurality of test signals according to the change of state of the selector switches and sends the generated test signal to the differential signal cable via one connector, and a signal receiving circuit that receives the test signal transmitted through the differential signal cable via the other connector and decides the success or failure of transmission of the test signal through the differential signal cable based on the received test signal and pre-stored data of the plurality of test signals.

A device for deciding characteristics of a differential signal cable at a transmission rate of not less than 10 G baud includes a selector switch that changes a transmission rate or an output power of a test signal to be supplied to the differential signal cable, a signal transmitting circuit that generates a test signal at a different transmission rate or output power as one of the predetermined number of plurality of test signals according to the change of state of the selector switches and sends the generated test signal to the differential signal cable via one connector, and a signal receiving circuit that receives the test signal transmitted through the differential signal cable via the other connector and decides the success or failure of transmission of the test signal through the differential signal cable based on the received test signal and pre-stored data of the plurality of test signals.

A method for simultaneous transmission of at least two high-frequency transmission signals via a common high-frequency line includes providing at least two input signals at respective inlet ports. The input signals are signals of a same carrier frequency. From the input signals, respective transmission signals are provided with different transmission frequencies from each other and from the carrier frequency by mixing the input signals using one frequency mixer each. The frequency mixers are supplied with respective mixer oscillator signals. The transmission signals are transmitted via the common high-frequency line. The mixer oscillator signals are provided from a same oscillator signal.

A method for simultaneous transmission of at least two high-frequency transmission signals via a common high-frequency line includes providing at least two input signals at respective inlet ports. The input signals are signals of a same carrier frequency. From the input signals, respective transmission signals are provided with different transmission frequencies from each other and from the carrier frequency by mixing the input signals using one frequency mixer each. The frequency mixers are supplied with respective mixer oscillator signals. The transmission signals are transmitted via the common high-frequency line. The mixer oscillator signals are provided from a same oscillator signal.

A system for coupling a modulated voltage signal onto a current loop between a host device and a field device, in various embodiments, can include a circuit and an impedance bridge. The circuit is configured to flow current from the field device between two terminals of an input circuit in the host device, wherein the two terminals are included in the current loop. The impedance bridge is positioned between the two terminals and configured to modulate impedance to convert the current in a field loop produced by the field device into terminal voltage modulation, without introducing a DC voltage burden to the current.

A system for distributing broadband signals via twisted pair wiring is disclosed. Various aspects of the system involve use of a broadband signal distribution interface device and/or a broadband line driver. In one aspect, a broadband signal distribution interface device includes a broadband signal interface configured to receive broadband radio frequency signals, and a plurality of broadband signal connections configured to distribute broadband radio frequency signals. The interface device also includes circuitry defining an upstream signal path and a downstream signal path and including a gain control circuit and a slope control circuit each positioned along the downstream signal path. The circuitry is configured to accommodate downstream transmission of the broadband signals onto twisted pair wiring.

A system for distributing broadband signals via twisted pair wiring is disclosed. Various aspects of the system involve use of a broadband signal distribution interface device and/or a broadband line driver. In one aspect, a broadband signal distribution interface device includes a broadband signal interface configured to receive broadband radio frequency signals, and a plurality of broadband signal connections configured to distribute broadband radio frequency signals. The interface device also includes circuitry defining an upstream signal path and a downstream signal path and including a gain control circuit and a slope control circuit each positioned along the downstream signal path. The circuitry is configured to accommodate downstream transmission of the broadband signals onto twisted pair wiring.

A physical unidirectional communication apparatus and method intended to utilize a structure that exploits an electrical signal by which data cannot be transmitted and to guarantee the reliability of data transmission via a transmission method that uses the structure. The physical unidirectional communication apparatus includes a unidirectional data transmission line, a data reception status transmission line, an internal network connection system unit for performing communication with an internal network transmission host and transmitting transmission data to an external network connection system unit through the unidirectional data transmission line, and the external network connection system unit for performing communication with an external network reception host, receiving the transmission data from the internal network connection system unit, generating reception status information of the transmission data, and transmitting the reception status information to the internal network connection system unit through the data reception status transmission line.

A physical unidirectional communication apparatus and method intended to utilize a structure that exploits an electrical signal by which data cannot be transmitted and to guarantee the reliability of data transmission via a transmission method that uses the structure. The physical unidirectional communication apparatus includes a unidirectional data transmission line, a data reception status transmission line, an internal network connection system unit for performing communication with an internal network transmission host and transmitting transmission data to an external network connection system unit through the unidirectional data transmission line, and the external network connection system unit for performing communication with an external network reception host, receiving the transmission data from the internal network connection system unit, generating reception status information of the transmission data, and transmitting the reception status information to the internal network connection system unit through the data reception status transmission line.