| 摘要 |
A system (10) for monitoring the ingress of noise into the return path (14) of a two-way CATV network comprises a detector circuit (16, 116) coupled to the return path (14) to receive a signal from the return path (14). The detector circuit (16, 116) provides an output signal indicative of the signal coupled from the network. A peak follower circuit (20, 120) coupled to the detector circuit (16, 116) stores a peak detected output signal from the detector circuit (16, 116). Illustratively, the peak follower circuit (20, 120) is coupled to the detector circuit (16, 116) through a filter circuit having a passband, for example, a low pass filter (18, 118). The peak follower circuit (20, 120) stores a peak detected output signal within the passband. A mixer (128) may be included for mixing the signal from the network with a local oscillator (126) frequency to produce a mixed signal, and for supplying the mixed signal to the detector circuit (16, 116).
|
