SPLITTER

摘要

In a splitter, a first duplexer including a first transmit filter and a first receive filter at a first antenna terminal and a second duplexer including a second transmit filter and a second receive filter at a second antenna terminal are connected to each other. A second transmit band of the second transmit filter and a second receive band of the second receive filter are positioned in a frequency range between a first transmit band of the first transmit filter and a first receive band of the first receive filter. Each of the second transmit filter and the second receive filter of the second duplexer includes an elastic wave filter. The elastic wave filter includes a high acoustic velocity film defining a high acoustic velocity member, a low acoustic velocity film through which transversal waves propagate at a lower velocity than those propagating through the high acoustic velocity film, a piezoelectric film disposed on the low acoustic velocity film, and IDT electrodes disposed on the piezoelectric film, which are stacked on each other in this order.

主权项

1. A splitter comprising:
a first duplexer including a first antenna terminal connected to an antenna, a first transmit filter connected to the first antenna terminal and including a first transmit band, and a first receive filter including a first receive band; and a second duplexer including a second antenna terminal connected to the antenna, a second transmit filter connected to the second antenna terminal and including a second transmit band, and a second receive filter including a second receive band; wherein the second transmit band and the second receive band are in a frequency range between the first transmit band and the first receive band; and each of the second transmit filter and the second receive filter of the second duplexer includes an elastic wave filter, and the elastic wave filter includes a high acoustic velocity member through which bulk waves propagate at a higher acoustic velocity than elastic waves propagating through a piezoelectric film, a low acoustic velocity film which is stacked on top of the high acoustic velocity member and through which bulk waves propagate at a lower acoustic velocity than bulk waves propagating through the piezoelectric film, the piezoelectric film stacked on top of the low acoustic velocity film, and an IDT electrode stacked on top of the piezoelectric film.