HP-Agilent/Keysight 788C

The HP 780-series Directional Detectors are directional couplers with built-in crystal detectors. The couplers have flat frequency response and good directivity, while the detectors also have good frequency response plus high sensitivity. The configuration of the directional detector reduces the number of ambiguities over the standard system of separate coupler and detector and makes possible tighter correlation between main-arm power and detected signal. The directional detector is well-suited to closed-loop level- ing applications, for it permits establishment of a leveled- power point anywhere in a system irrespective of the char- acteristics of intervening cables, connectors, etc.