| 摘要 |
PURPOSE: A device and a method for eliminating a local frequency of a wireless communication system are provided to configure an AGC(Auto Gain Control circuit) having a large input dynamic range for enabling dynamic trace according to the change of the strength of a local frequency, and to attenuate a local frequency included in an outputted RF(Radio Frequency) signal to a local frequency outputted in the AGC. CONSTITUTION: A mixer(205) mixes a modulated IF(Intermediate Frequency) and a local frequency, to generate an RF(Radio Frequency) signal. A driving amplifier(207) amplifies an output of the mixer(205). A phase converter(225) converts the local frequency into a reverse phase. An AGC(Auto Gain Control circuit,227) regulates a local frequency gain of the reverse phase, to make the strength of the local frequency identical with an output of the driving amplifier(207). A summer(209) sums outputs of the driving amplifier(207) and the AGC(227), to eliminate a local frequency components included in the RF signal. A filter(211) filters the RF signal outputted in the summer(209) to a transmission band, for outputting. A power amplifier(213) amplifies the RF signal outputted in the filter(211) to a transmission power level, for outputting. A switch(215) supplies a transmission signal outputted in the power amplifier(213) to a filter(217). And the filter(217) outputs the transmission signal through an antenna(219).
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