| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an IQ mismatch correction circuit which corrects a frequency-dependent IQ mismatch while continuously performing a reception process. <P>SOLUTION: The correction circuit which performs a correction process by using a pair of first order or higher order digital filters 11 and 12 to I-phase and Q-phase input signals, two or more control circuits 19 and 20 which generate two or more control variables for deriving two or more coefficients of each transfer function of the digital filter respectively, and one or more pair of analysis filters 17 and 18 which change a frequency characteristic of the corrected I-phase and Q-phase output signals so as to obtain the frequency characteristic different from that of each original signal are included. A first control circuit measures a time-averaged IQ phase mismatch state between the I-phase and Q-phase output signals, and feeds back it to each digital filter as a first control variable. A second control circuit measures the time-averaged IQ phase mismatch state between the output signals of I-phase and Q-phase sides of a pair of the analysis filters, and feeds back it to the each digital filter as a second control variable. <P>COPYRIGHT: (C)2010,JPO&INPIT |
