Passive Sensing Node Network for Monitoring Performance of RF Connector-Coaxial Cable System

A passive sensing node technology is introduced for monitoring the integrity of RF coaxial transmission lines and associated RF connectors in the UHF range of frequencies. Each passive sensing node is powered by a transmission line coupler inside the coaxial cable. Passive sensing node sensing elements, fineline interconnect metallurgy, transmission line coupler, and electronics are packaged on a molded interconnect device. The molded interconnect device structure and substrate material are designed to minimize electrical disturbance to the coaxial cable and preserve coaxial cable mechanical integrity. A custom integrated circuit on the molded interconnect device measures coaxial cable RF performance parameters, harvests operating power for the custom integrated circuit, and enables remote telemetry. The passive sensing node operates with a 60 μW power listening mode and a 900 μW power active mode for operating the three primary sensors, signal processing circuits, and backscatter telemetry. This paper proposes a network of passive sensing nodes in a coaxial cable system, describes the operation of the sensors in each passive sensing node, and provides a mathematical model for the transmission line coupler. Copyright © 2014 IFSA Publishing, S. L.