Abstract: A monitoring system for an transmission line, such as a multi-channel television broadcasting antenna feed line, gathers data about the physical and electrical condition of the line in real time. The system can detect and localize deterioration and other time-dependent faults in the transmission line by the tendency of faults to produce reflections back to the transmitter that were not part of the original characterization of a particular installation. Some kinds of faults, identified early enough, can be corrected without replacing components, and especially without shutting down the transmission line during prime viewing hours. Other faults can be detected in time to order replacement parts before the underlying problem becomes severe, and to allow servicing during periods of low demand.

Abstract: A directional filter and/or combiner for high-power RF signals provides optimized power handling and allows cascading of waveguide filter elements. The use of circular filter cavities allows the filter to have pseudoelliptic coefficients while ensuring phase stability and maximizing power handling.