| 摘要 |
[Problem] To provide a high-performance composite circuit that supports broader bandwidth, a circuit device, a circuit board, and a communication device. [Solution] A composite circuit 10 comprises a first diplexer section 20A through which the positive-phase signal of a balanced signal passes and a second diplexer section 20B through which the reverse-phase signal of the balanced signal passes. A balun section 40 has a low-frequency-side first balun component 41 and a high-frequency-side second balun component 42. The first balun component 41 and the second balun component 42 have a plurality of lines L12 and L15, respectively, which are connected to the first diplexer section 20A and pass signals of two different frequency bands, as well as a plurality of lines L13 and L16, respectively, which are connected to the second diplexer section 20B and pass signals of two frequency bands. Lines L12 and L13 constitute a pair of balanced lines 46, and lines L15 and L16 constitute a pair of balanced lines 46. Furthermore, the first balun component 41 and second balun component 42 each have an unbalanced line 45. |
