Surface acoustic wave filter, and antenna duplexer and communication equipment using the same

Abstract

The present invention provides a surface acoustic wave filter and others that reduce ripples in a reception frequency band while ensuring sufficient attenuation in a transmission frequency band. A surface acoustic wave filter includes a surface acoustic wave resonator that allows a reception frequency band to pass while attenuating a transmission frequency band, and a surface acoustic wave filter connected in series with the surface acoustic wave resonator to allow the reception frequency band to pass while attenuating the transmission frequency band. An inductor is connected to one end of the surface acoustic wave resonator, a connection point between the surface acoustic wave filter and the surface acoustic wave resonator, and/or the other end of the surface acoustic wave resonator.

Dependencies are inferred from the claim text.