| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high frequency amplifier which can ensure good high frequency performance while reducing the mounting area of components used, and to provide a portable telephone employing it. <P>SOLUTION: The high frequency amplifier comprises an input matching circuit 11 for matching the impedance of a high frequency signal inputted externally and modulated by a plurality of modulation systems, power amplifiers Tr1 and Tr2 performing power amplification of the high frequency signal impedance of which is matched in the input matching circuit, an RF switch 12 which delivers the high frequency signal outputted from the power amplifier while switching depending on the modulation system, and a plurality of outut matching circuits 20 and 21 for matching the impedance to optimize power efficiency and adjacent channel leakage power ratio for each high frequency signal outputted from the RF switch. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
