| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high frequency circuit apparatus used for a multi-band mobile phone for reducing an insertion loss and preventing increase in current consumption even in the EDGE (enhanced data rates for GSM evolution) system wherein the phase of a transmitted carrier wave is required to be finely controlled. <P>SOLUTION: The high frequency circuit apparatus consists of: a transmission path 20 for transmission/reception signals of respective frequency bands from a plurality of communication systems; a branching circuit 22 for branching the signals to a reception path 19; a reception changeover switch 30 for switching the reception path to each of reception sections; and SAW filters 10, 11, 12 connected to the respective reception sections 16 via transmission lines 33, 34, 35. The branching circuit 22 is configured to include isolators 7, 8 on respective transmission paths with different frequencies. Thus, a diplexer and a high frequency switch usually installed in a range from a power amplifier to an antenna on the transmission paths can be eliminated, and hence increase in the current consumption is prevented, and the circuit board of the high frequency circuit apparatus and the mobile phone itself can be downsized and cost-reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
