| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless transmitter/receiver that can accurately cancel or reduce a DC offset of a transmitting part by using an amplifying circuit of a receiving part, and to provide a radio transmitting method. SOLUTION: A DC offset of a VGA 15 is measured by selecting a contact e of a switch 14. Then, the gain of the VGA 15 is set at an appropriate value, a contact of the switch 14 is successively switched as d, c and b, and each of output values of an ADC 16 for the respective cases is measured with the input to a DAC 17 set at zero. Then, the DC offset of the VGA 15 is removed, the DC offset value of each circuit block, such as DAC 17 constituting a transmitting part 3 is calculated, and parameters are set so that the DC offset value of each circuit block is minimized. COPYRIGHT: (C)2009,JPO&INPIT
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