| 摘要 |
PURPOSE: To provide a system which detects and controls the gain and phase errors of a direct conversion receiver having a pair of signal channels for carrying and I- and Q-base band signal components which have quadrature phases and are the function of a phase angle. CONSTITUTION: A gain and phase error detecting and control system 100 operates by generating the I'- and Q'-base band signals corresponding to sin(2θ) and cos(2θ). The I'- and Q'-base band signals are filtered 110 and 111 after the signals are normalized with respect to their amplitudes and the signals DCI and DCQ corresponding to their DC components are generated. Since it is known that the signals DC and DCQ are separately correlated with gain and phase errors, the signals DCI and DCQ are used for correcting such errors that exist between original I- and Q-base band signal components by adjusting the base-band signal components.
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