Cables (e.g., waveguides, coaxial cables, and twisted-pair cables) are the most commonly used components in RF and microwave communication systems. They are also the primary cause of failures. During maintenance of these systems, engineers and technicians must measure cable performance (e.g., return loss and variable standing wave ratio [VSWR]) and simultaneously identify the location and cause of faults (e.g., poor insulation, kinks, or water ingress). Performing these tests requires an antenna and cable analyzer, a network analyzer, a signal generator, and a power meter, all of which must be transported and set up for field testing. This process is prone to errors, and the instruments can be damaged by accidents.
The new Time Domain Reflectometry (TDR) cable measurement option enables TDR measurements on the antenna and cable analyzer. With this feature, Keysight FieldFox analyzers become the ideal tool for any cable system test. This option complements the analyzers' return loss (RL) and distance to fault (DTF) measurements. It measures impedance changes in the cable and helps identify specific faults, while the analyzer's RL measurement capability detects mismatches in cable connections, and the DTF capability indicates faults and poor connections along the cable.
Measuring long microwave cables in the field is a complex task, requiring instruments that offer high dynamic range and fast, reliable results. The new Extended Range Transmission Analysis option for FieldFox analyzers addresses one of the major challenges of measuring cables in the field: measuring long microwave cables with in-situ losses. Accessing both ends of the cables or the waveguide simultaneously is difficult. Using a signal generator with a broadband detector or power sensor to measure cable loss can be slow, prone to external interference, and doesn't support high dynamic range. Deploying a benchtop solution in the field for measurement is also impractical due to its large size and high cost.
Extended-range transmission analysis deploys two FieldFox instruments at each end of the cable being measured. One analyzer acts as the source, and the other as the receiver. The steps of the two instruments are synchronized using hardware triggers. Employing Keysight's proprietary InstAlign spectrum analysis technique, engineers and technicians can use this setup to perform highly accurate cable loss measurements without calibration or warm-up time. This option can also be configured with frequency offset to measure devices such as mixers and converters.
“Bringing precision to the field is the core strength of Keysight’s FieldFox analyzers,” says Dan Dunn, General Manager of RF Handheld Instruments at Keysight. “Our new measurement options further enhance this concept, enabling customers to use FieldFox to perform comprehensive cable testing in the field and consistently obtain the quality measurements they expect from Keysight.”.
Additional cable testing functionality
In addition to new cable testing capabilities using TDR and extended-range transmission analysis, FieldFox analyzers offer several features that make them particularly well-suited for cable testing. They can measure RL, VSWR, impedance, insertion loss, and s-parameters with magnitude and phase. FieldFox analyzers can also be used for spectrum analysis and vector voltmeter measurements.
