| 摘要 |
PROBLEM TO BE SOLVED: To prevent the scale of a circuit and the amount of data to be transmitted from being increased when reducing power consumption by controlling the degree of an LPF in accordance with a plurality of interference waves. SOLUTION: An LPF 12 comprises three secondary LPFs having the same configuration, and outputs a main signal after canceling an adjacent ch signal or a next adjacent ch signal contained in a communication signal. A BPF 14 extracts the adjacent ch signal and the next adjacent ch signal from the communication signal, with a difference in bandwidth. A Power DET 15 outputs power of the adjacent ch signal and the next adjacent ch signal extracted in accordance with voltage values. Comparators 16, 17 compare the voltage values with reference voltages 18, 19 corresponding to the difference of the bandwidth, and detects the next adjacent ch signal and the adjacent ch signal. The LPF 12 automatically switches the secondary LPFs to serial connection in three stages based on the next adjacent ch signal and the adjacent ch signal. COPYRIGHT: (C)2011,JPO&INPIT |
