Multiplexer including filter with two types of acoustic wave resonators

A filter assembly comprising:

• a first filter coupled to a common node, the first filter configured to provide a single-ended radio frequency output signal;
• and
• a second filter coupled to the common node and configured to filter a radio frequency signal, the second filter including acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node, the series acoustic wave resonator of the second type having a higher suppression of a second harmonic of a radio frequency signal than the acoustic wave resonators of the first type.

A wireless communication device comprising:

• an antenna;
• and
• a multiplexer coupled to the antenna, the multiplexer including a receive filter configured to provide a single-ended radio frequency receive signal, and a transmit filter including bulk acoustic wave resonators and a series surface acoustic wave resonator coupled between the bulk acoustic wave resonators and the antenna, the transmit filter configured to filter a transmit radio frequency signal.