| 摘要 |
PURPOSE:To largely reduce carrier leakage in a mixer circuit. CONSTITUTION:A high frequency signal Sr received by a couple of 1st mixer circuits 11, 21 of an orthogonal form is frequency-converted into a couple of 1st intermediate frequency signals S11, S21 of a base band. The 1st intermediate frequency signals S11, S21 of 2nd mixer circuits 13, 23 of an orthogonal form are frequency-converted into a couple of prescribed 2nd intermediate frequency signals S13, S23. The original signal is demodulated from a 2nd intermediate frequency signal S3 through the arithmetic operation result of the 2nd intermediate frequency signals S13, S23. A couple of detection circuits 31, 41 are provided, which receives output signals S13, S23 of the 2nd mixer circuits 13, 23 and detects a carrier leak component included in the output signals S13, S23. The output signals of the detection circuits 31, 41 are fed to the 2nd mixer circuits 13, 23, in which a DC balance is corrected to decrease the carrier leakage component.
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