| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain high demultiplexing properties, in a circuit for demultiplexing a communication signal into three frequency bands of different frequencies. <P>SOLUTION: A demultiplexer is configured by disposing, on a first path, a first band-pass filter bpf1 which makes a signal of a first frequency band pass on a second path; a second band-pass filter bpf2 for passing a signal of a second frequency band at a frequency side higher than the first frequency band; and on a third path, a third band-pass filter bpf3 for passing a signal of a third frequency band, at a frequency side higher than the second frequency band. In order to improve the demultiplexing properties, first, second and third parallel resonance circuits (X1-X3) are provided between the first, second and third band-pass filters (bpf1-bpf3) and a common terminal Pc; and further, on the first and second paths, a transmission line is provided as phase adjusting circuits (Y1, Y2) between the band-pass filters and the parallel resonance circuits. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
