| 摘要 |
<P>PROBLEM TO BE SOLVED: To shorten a time needed until regular reception is available by rapidly converging a fluctuation in a DC offset voltage caused when a power source is turned on, for example, when intermittent reception starts, while maintaining receiving performance. <P>SOLUTION: Impedance switching circuits 182 and 192 can increase cutoff frequencies by making impedance values of HPFs 108 and 109 small and decrease the cutoff frequencies by making the impedance values large to the contrary. In intermittent receiving operation, the power source of a wireless part is turned on and then the power source of a base band is turned on. Consequently, the fluctuations in the DC offset voltages of I and Q signals are caused at input ends of A/D converters 110 and 111. The fluctuation is converged into a stationary state in a short period of time by increasing the cutoff frequencies of the HPFs 108 and 109. Then the cutoff frequencies of the HPFs 108 and 109 are put back to proper values and the reception quality is held nearly constant. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
