| 摘要 |
<p>Feeder cable insertion loss detection in a transmission system without interfering with normal operation including injecting a non-interfering signal (210) at a predetermined frequency onto a cable (240) providing normal operating signals (222) to narrowband device (230) at another predetermined frequency, measuring the amplitude of the injected signal, measuring the amplitude of a reflected signal, the injected signal being reflected by the narrowband device and processing the amplitude of the injected signal and the amplitude of the reflected signal to derive a current insertion loss for the cable. Further the current insertion loss is compared to a prior insertion loss and the cable is determined to be defective when the current insertion loss differs from the prior insertion loss by predetermined amount. The arrowband device (230) is an antenna, a low noise amplifier, a power amplifier, a filter or an RF-to-light converter for a fiber optic distribution network.</p> |
