| 摘要 |
PROBLEM TO BE SOLVED: To correct not only a level error but also phase deviation and to suppress the generation of the unrequired frequency components of high frequency band signals as much as possible. SOLUTION: A base band signal generator 1 generates base band signals composed of common-mode signals and quadrature signals whose phases are shifted for 90 deg. from each other, based on frequency setting data signals. A quadrature modulator 16 generates the high frequency band signals for which the base band signals are shifted to a high frequency area by local oscillation frequency signals. In this frequency converter provided with the base band signal generator 1 and the quadrature modulator 16, a detection circuit 11 for detecting the level values and phase values of the common-mode signals and the quadrature signals and a control circuit 14 for calculating the level error and a phase difference between the common-mode signals and the quadrature signals based on the detected results and controlling the base band signal generator 1 so as to output the base band signals for which the level values of the common-mode signals and the quadrature signals are the same and the phase difference between both signals is 90 deg. according to the level error and the phase difference are provided. |
