| 摘要 |
<P>PROBLEM TO BE SOLVED: To monitor and adjust an I/Q phase bias accurately in an I/Q quadrature modulation transmitter. <P>SOLUTION: The I/Q quadrature modulation transmitter comprises an I-branch 102, a Q-branch 103 provided with a phase element 108, a tap 110, and an I/Q phase differential monitoring apparatus 113. The I/Q phase differential monitoring apparatus 113 is located between the tap 110 and the phase element 108 for monitoring the I/Q phase difference. The I/Q phase differential monitoring apparatus 113 is provided with a squarer 114 for performing a square operation to a signal received from the tap 110, I-branch data 104, Q-branch data 105, a multiplier 116 for multiplying an output 115 from the squarer 114, an averager 118 for averaging an output 117 from the multiplier 116. By controlling a phase shift amount of the phase element 108 in accordance with the monitoring result, the I/Q phase differential is adjusted. <P>COPYRIGHT: (C)2008,JPO&INPIT |
