| 摘要 |
<p>A compact elastic wave duplexer is provided. The elastic wave duplexer includes a transmission filter chip and a reception filter chip mounted on a laminated board. An impedance matching circuit is formed inside the laminated board. The isolation characteristics in a transmission band and a reception band are improved. The balance between the two is improved. The elastic wave duplexer (1) includes a transmission filter chip (6) and a reception filter chip (7) each formed from an elastic wave filter chip and flip-chip bonded to a laminated board (43). A coil-shaped line including coil-shaped line patterns (52, 54, and 56) is formed inside the laminated board (43). The coil-shaped line serves as an impedance matching circuit. In plan view, the transmission filter chip (6) is disposed on one side of a center line (X) passing through the center of the laminated board (43) and extending between a first edge (43A) and a second edge (43B), and the reception filter chip (7) is disposed on the other side. The coil-shaped line is disposed on the side on which the reception filter chip (7) is disposed.</p> |
