DUPLEXER AND METHOD OF ISOLATING AN RX-BAND AND A TX-BAND

摘要

A duplexer (1) with two band-pass filters (5, 6) comprising film bulk acoustic wave resonators (FBAR) (8, 9, 10, 11, 12, 13) has an extra antiresonant circuit in order to block the transmission signal. It has an extra resonant circuit in order to allow the desired receive signal to pass. The antiresonant circuit comprises the first FBAR (11) and a parallel inductor (14). The resonant circuit comprises the first FBAR (11) and a series inductor (7).