| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain cost reduction and remediation of oscillation defect or frequency switching response speed deceleration by enabling a plurality of frequency signals to be received, while using one local oscillator, without varying an oscillation frequency. <P>SOLUTION: In a multi-channel communication apparatus, two frequencies in a relationship of a desired wave and an image are used as first and second channels CH1 and CH2 and a mixer includes two mixer blocks (2, 5, 6, 9, 11) (3, 7, 8, 12, 13). Frequency signals of the channels to be the image between one mixer block and another mixer block are output while inverting their phases to each other and canceled by an adder 10. Furthermore, on a pre-stage of a mixer 27, there are provided a first filter 23 with the first channel as a pass band and the second channel as a block band and a second filter 25 with the second channel as a pass band and the first channel as a block band and these filters are changed over by switches 22, 26, 24, 28. <P>COPYRIGHT: (C)2010,JPO&INPIT |
