| 摘要 |
An improved channel detection device for detecting a channel. This channel detecting device comprises a channel-search circuit (3), which decides it when a frequency is detected by a search sweep with a frequency sweep signal on that channel whether or not the detected frequency is within a frequency range relating to that channel. The channel-search circuit (3) is provided with a search sweep controller (32). This controller can include a sweep stop timing circuit (320) for stopping a search sweep by the frequency sweep signal, when the output of that channel rises in response to the search sweep by the frequency sweep signal, and a sweep reopen timing circuit (322) for deciding it, when the level of the output of the channel to the frequency sweep signal fixed at the detected frequency is lower than a threshold value, that the detected frequency is not within the frequency range relating to that channel, thereby to reopen the search sweep. |
