| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To form a circuit without using non-linear elements such as a transistor and reduce IQ amplitude errors and IQ phase errors. <P>SOLUTION: An IQ modulation/demodulation circuit is provided with a four- phase input/output RC poly-phase filter 14 which inputs an oscillator signal from an oscillator signal input terminal VCOIN and outputs signals of 0°, 90°, 180°, and 270°. The signals of 0°and 180°are supplied to an I signal mixer 13. The signals of 90°and 270°are supplied to a Q signal mixer 12. The IQ modulation/demodulation circuit performs IQ demodulation by inputting a high frequency signal into the mixers 12 and 13. The circuit performs IQ modulation by inputting Q signal and I signal into the mixers 12 and 13. Since the circuit is composed of a resistance being a passive element and a capacitor, the IQ amplitude errors and the IQ phase errors are reduced. <P>COPYRIGHT: (C)2004,JPO</p> |
