| 摘要 |
PROBLEM TO BE SOLVED: To cope with a wide band wireless communication system without the need for considerable revision of the circuit scale. SOLUTION: The RF front end circuit is provided with: a reception connection switch 20 located between an antenna terminal 4 and a reception terminal 2; a reception terminal grounding switch 23 located between the reception terminal 2 and a ground terminal 11; a transmission connection switch 30 located between the antenna terminal 4 and a transmission terminal 3; and a transmission terminal grounding switch 33 located between the transmission terminal 3 and a ground terminal 15, and the reception connection switch 20 includes: a band pass filter 26a with a first pass band; switching transistors 25a, 27a for switching the band pass filter 26a; a band pass filter 26b with a second pass band different from the first pass band and connected in parallel with the band pass filter 26a; and switching transistors 25b, 27b for switching the band pass filter 26b. COPYRIGHT: (C)2005,JPO&NCIPI
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