| 摘要 |
PROBLEM TO BE SOLVED: To prevent an unnecessary image wave signal factor from being superimposed into a desired wave signal factor. SOLUTION: An input signal entered in an input terminal 1 is entered in mixers 2 and 4 and subjected to down-conversion with a local signal having a phase difference of 90 degrees to obtain an I-signal and a Q-signal. The output signal of the mixer 4 delays 90 degrees in phase through a phase shifter 6. In an adder 7, the sum of the I-signal and Q-signal is generated, and in an subtracter 8, a difference signal of the I-signal and Q-signal is generated. The sum signal and the difference signal are entered into band pass filters 9 and 10 to cut signals in an unnecessary frequency band. Then, the signals are converted to digital signals in AD converters 11 and 12 and entered in a signal processor 13. In the signal processor, a correlation signal of the sum signal and the difference signal is generated and an image wave signal factor included in the sum signal is removed by using the correlative signal and the difference signal. COPYRIGHT: (C)2004,JPO
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