Transmission system for transmitting rf signals, power and control signals via rf coaxial cables

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.