| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vector modulation signal generation apparatus where output level error caused by carrier leak of a quadrature modulator is reduced for the purpose of calibrating its output level with high accuracy. <P>SOLUTION: The vector modulation signal generation apparatus is configured such that an ALC loop is formed by inputting a feedback voltage outputted from a feedback circuit 7 as a control signal to a level variable means 5 when a quadrature modulation means 4 carries out quadrature modulation by using a calibration signal outputted from a complex sine wave signal generating means 24, and a sample-hold means 8 samples and holds the feedback voltage when the ALC loop is formed in the case that the quadrature modulation means 4 carries out quadrature phase modulation by using a base band signal and the hold voltage is input to the level variable means 5 as the control signal, and a complex sine wave signal comprising an I signal and a Q signal input to the quadrature modulation means 4, the amplitude of which is equal to each other and the phase difference of which is 90 degrees, and the frequency of which is higher than a response frequency band of the ALC loop is adopted for the calibration signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
