| 摘要 |
PROBLEM TO BE SOLVED: To facilitate addition of a new channel in a digital broadcast receiver. SOLUTION: An RF signal of a channel selected by a BPF 3 is converted into an IF signal A in a mixer circuit 17 and is distributed into two paths with a first splitter 22. One signal is input into an IF SAW 23 for viewing and listening, and the other is input into an IF SAW 41 for adjacent channel detection. The output of the IF SAW 41 is input to one of the input terminals of a subtractor 45 via an IF amplifier 43. The output of the IF SAW 23 is input to the other of the input terminals of the subtractor 45 via an IF amplifier 25, a compensating amplifier 31, and a second splitter 33. Based on the output level of this subtractor 45, it is determined whether there is an adjacent channel. Moreover, by collating with a channel list 53, the existence of an additional channel is detected. If there is an additional channel, its notification is issued and channel search is urged. COPYRIGHT: (C)2008,JPO&INPIT
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