| 摘要 |
<p>A continuous wave (CW) leaky cable sensor for an intrusion detector is comprised of a pair of elongated parallel cables, one for establishing an RF field and the other for receiving the field. A modulator is connected at an intermediate location of the receiving (or transmitting) cable, subdividing a detection zone into detection regions on each side of the modulator. The modulator selectively modifies a signal received by a portion of the receive cable connected to its input. By processing the signal at the output of the receive cable the detection region for either side of the modulator in which an intrusion has occurred can be determined. The resolution of a CW sensor is thus increased at low cost. Multiple modulators can be used at spaced locations increasing the number of detection regions, and thus the resolution.</p> |
