| 摘要 |
A multiplexer includes: a first band-pass filter for a first channel, which is formed in a microstrip line on a dielectric substrate and has a first branching characteristic having a center frequency of f 1 and an attenuation pole at a frequency of fa 1; and a second band-pass filter for a second channel, which is formed in a microstrip line on a dielectric substrate and has a second branching characteristic having a center frequency of f 2 and an attenuation pole at a frequency of fa 2. The following relationships (1) to (5) are satisfied: (1) f 1 <f 2; (2) f 1 <fa 1; (3) fa 2 <f 2; (4) f 2 -fa 1 <(f 2 -f 1 )/2; and (5) fa 2 -f 1 <(f 2 -f 1 )/2. The second branching characteristic exhibits -20 dB or less at the frequency of fa 1 and the first branching characteristic exhibits -20 dB or less at the frequency of fa 2.
|
