WAVE DEMULTIPLEXER

摘要

An elastic wave demultiplexer in which a transmission filter chip and a reception filter chip are mounted on a laminated board and an impedance matching circuit is fabricated in the laminated board. The isolation characteristic of the transmission and reception bands is improved and their balance is enhanced, thus providing a small-size demultiplexer. A transmission filter chip (6) and a reception filter chip (7) each composed of an elastic wave filter chip are mounted on a laminated board (43) by flip-chip bonding. In the laminated board (43), a coil-like path including coil-like path patterns (52, 54, 56) constituting an impedance matching circuit is formed. When viewed from above, with respect to the center line X passing through the center of the laminated board (43) and connecting a first end part (43A) to a second end part (43B), the transmission filter chip (6) is disposed on one side and the reception filter chip (7) is disposed on the other side.The coil-like path is disposed on the same side as the reception filter chip (7). Such an elastic wave demultiplexer (1) is provided.