# US 7,412,208 B1 · Transmission system for transmitting RF signals, power and control signals via RF coaxial cables > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,412,208 B1 - Document ID: US7412208B1 - Status: Granted - Kind: B1 - Application number: 10/094,741 - Filed: 2002-03-11 - Granted: 2008-08-12 - Earliest claimed: 2002-03-11 - Assignees: Agilent Technologies, Inc. - Inventors: Terrence R. Noe; Leonard M. Weber - Web page: https://patentgrep.com/patent/US7412208B1 ## CPC - H04B 3/548: {the power on the line being DC (arrangements for feeding power H04L12/10; extracting feeding power from signals H04L25/02)} - H04L 43/50: Testing arrangements - H04B 2203/5441: Wireless systems or telephone - H04B 2203/5483: using coupling circuits - H04B 2203/5491: using filtering and bypassing - H04B 2203/5495: having measurements and testing channel - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A transmission system for RF signals, power and control signals over RF coaxial cables is disclosed. A coaxial cable line interconnects two devices, such as an instrument and a remote coupler. A control signal (e.g., data bit) and RF signals are multiplexed onto the coaxial cable line using a bias network at each end of the coaxial cable. In certain embodiments, power is generated at the coupler based on the state of the control bits. Each coaxial cable carries one control bit on the center conductor of the cable. A table maps the states of the one or more control bits to the desired states in the remote coupler. The all-zeroes state for the control bits is disallowed, such that at any given time, at least one of the control lines is high (e.g., at +5V). A passive network at the coupler generates the power voltage for the coupler from the control bits. In further embodiments, a power supply filter is provided at the coupler to supply power to the coupler during transitions of the passive network. ## Claims ### Claim 1 A transmission system for providing RF signals, power and control signals to a device, comprising: at least one bias network within the device, said at least one bias network being capable of being connected to at least one respective RF coaxial cable to receive respective multiplexed RF signals and controls signals, said at least one bias network being further capable of de-multiplexing the RF signals and control signals; at least one control line being connected to a respective one of said at least one bias network to receive a respective one of the de-multiplexed control signals; control circuitry within the device connected to said at least one control line to receive all of the de-multiplexed control signals, said control circuitry being configured to control the state of the device based on the states of the received de-multiplexed control signals; and a passive network within the device connected to said at least one control line to receive all of the de-multiplexed control signals and provide power to said control circuitry based on the state of each of the de-multiplexed control signals. ### Claim 2 (depends on 1) The system of claim 1, wherein said at least one bias network comprises a plurality of bias networks and said at least one RF coaxial cable comprises a plurality of RF coaxial cables, each of said plurality of bias networks being connected to a respective one of said plurality of RF coaxial cables. ### Claim 3 (depends on 1) The system of claim 1, wherein said passive network comprises at least one diode, each said at least one diode being connected to a respective one of said at least one control line. ### Claim 4 (depends on 1) The system of claim 1, further comprising; a power line interconnecting said passive network and said control circuitry to provide the power from said passive network to said control circuitry. ### Claim 5 (depends on 4) The system of claim 4, further comprising: a power supply filter connected to said power line to supply power to said control circuitry during transitions of said passive network. ### Claim 6 (depends on 1) The system of claim 1, further comprising: a table for mapping the states of the de-multiplexed control signals to the desired states of said control circuitry in the device, said table disallowing the all-zeroes state for all of the de-multiplexed control signals to enable the power to be supplied to said control circuitry of the device. ### Claim 7 (depends on 1) The system of claim 1, wherein said at least one bias network further comprises: a capacitor connected to pass the RF signals from the multiplexed RF signals and control signals; an amplifier connected to receive the de-multiplexed RF signals and amplify the de-multiplexed RF signals; and a low pass filter connected to pass the control signals from the multiplexed RF signals and control signals. ### Claim 8 A method for providing RF signals, power and control signals from a first device to a second device, comprising: multiplexing the RF signals and control signals onto at least one RF coaxial cable interconnecting the first device and the second device; de-multiplexing the RF signals and control signals at the second device; controlling the state of the second device based on the states of the received de-multiplexed control signals; and providing a supply of power, from which the second device draws operating power, based on the state of each of the dc-multiplexed control signals. ### Claim 9 (depends on 8) The method of claim 8, wherein said step of multiplexing further comprises: multiplexing respective RF signals and control signals onto respective ones of a plurality of RF coaxial cables. ### Claim 10 (depends on 8) The method of claim 8, wherein said step of providing power further comprises: forward-biasing at least one diode based on the state of all of the de-multiplexed control signals to provide power to the second device. ### Claim 11 (depends on 8) The method of claim 8, wherein said step of providing power further comprises: supplying power to said control circuitry during transitions of the states of the de-multiplexed control signals. ### Claim 12 The method of Clan 8, wherein said step of controlling further comprises: mapping the states of the de-multiplexed control signals to the desired states of said control circuitry in the second device to control the state of the second device. ### Claim 13 (depends on 12) The method of claim 12, wherein said step of providing power further comprises: disallowing the all-zeroes state for all of the de-multiplexed control signals to enable the power to be supplied to said control circuitry of the second device.