| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable simple and accurate adjustment of carrier leakage. <P>SOLUTION: In a method for detecting a carrier leakage adjusting point in an orthogonal modulator 14 to cancel carrier leakage, included in a modulation signal a issued from the modulator 14, such D.C. voltages which cause the output of the orthogonal modulator to become a certain reference level is added to signals I and Q, under the conditions that the signal Q have zero signal level, the D.C. voltages are varied to search for 3 or more combinations of pairs of the D.C. voltages to be added to the signals I and Q, whereby the level of the modulation signal becomes a reference level. Since the 3 or more combinations of the D.C. voltages searched are positioned on the circumference of a virtual circle 13 drawn in a two-dimensional coordinate system, having ordinate and abscissa for the pairs of D.C. voltages to be added to the signals I and Q, the coordinate point at the center of the virtual circle is calculated as the carrier leakage adjusting point. <P>COPYRIGHT: (C)2003,JPO |
