| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for eliminating a switching noise when controlling an attenuation means. <P>SOLUTION: The attenuation means capable of increasing/decreasing an attenuation amount is interposed in a signal route between an input end and a tuner, and normally attenuation is executed for transmission to the next stage. The tuner includes an electric field strength-measuring means for measuring and outputting an input signal level, and is further provided with a control means for receiving signal level information measured by the tuner, performing data processing in a prescribed processing order, and outputting a switching control signal for switching so as to increase/decrease the attenuation amount of the attenuator element of the attenuation means on the basis of the result obtained by the data processing. The attenuation means includes the plurality of attenuator elements and the switching means and is configured to selectively utilize the attenuator elements. The control means executes control so that at least one of the plurality of attenuator elements is interposed and switching is performed to permit the attenuation means to send out signals inputted from the input end to the next stage without interruption. <P>COPYRIGHT: (C)2010,JPO&INPIT |
