| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a transmitter that performs impedance matching between parts appropriate to the band of a transmission signal after band switching and that performs more proper impedance matching in accordance with unintended changes of an element characteristic inside the parts due to aged deterioration. <P>SOLUTION: Transmitters (1,2 and 3) amplify a signal and transmit it via an antenna (101). The transmitters comprise: matching circuits (104, 105, 108 and 109) connected to an input side and an output side of amplifier units (106, 107, 301 and 302) for amplifying a generated transmission signal and outputting it; and level detecting units (110, 111) for inputting the amplified transmission signal via the matching circuits and detecting the signal level. When the transmitters select one from multiple transmission bands and generate the transmission signal,an impedance value appropriate to the transmission band is set to the matching circuits, and based on the detection result of the level detecting units after setting of the impedance value, fine adjustment of the set impedance value is made. <P>COPYRIGHT: (C)2012,JPO&INPIT |
