| 摘要 |
PURPOSE:To suppress the frequency error of a 2nd local oscillation signal by driving a switch to apply the 2nd local oscillation signal and the 2nd reference data to the input side of a comparison part. CONSTITUTION:The switches SW1, SW2, SW3 and SW5 are driven in the states shown by the dotted lines, and the switches SW4 and SW6 are driven in the states shown by the solid lines respectively. Then the necessary parts are connected respectively so that the frequency error of a 2nd local oscillation signal is suppressed. Thus the 2nd local oscillation signal of (f12+ or -DELTAepsilon2)/m frequency and the 2nd reference data of (f12)/m frequency are applied to the input side of a comparison part 3. Therefore the part 3 sends the control data corresponding to the frequency error DELTAepsilon2 of the 2nd local oscillation signal to a 2nd storage part 4b and a 2nd control voltage generating part 6. The part 4b stores the control data, and the part 6 generates the control voltage to apply them to a 2nd local oscillation circuit. In such a constitution, the error DELTAepsilon2 can be suppressed. |
