| 摘要 |
<p>By arranging a SAW filter in a high-frequency band circuit, it is possible to provide a high-frequency part not degrading pass characteristic of a low-frequency band even if impedance mismatch occurs. The high-frequency part includes: a diplexer (1) having a high-pass filter (102) and a low-pass filter (101) which are connected in parallel to an antenna port; a high-frequency band circuit connected to the high-pass filter (102); and a low-frequency band circuit connected to the low-pass filter (101). A filter causing impedance mismatch is connected to the high-frequency band circuit. The high-pass filter (102) includes a first series resonance circuit (102A) and a second series resonance circuit (102B). The first series resonance circuit (102A) has a resonance frequency which is a trap frequency of a transmission/reception signal of the low-frequency band. The second series resonance circuit (102B) has a resonance frequency which is a trap frequency of an unnecessary resonance generated in the pass characteristic of the filter of the low-frequency band side.</p> |
