Duplexer with enhanced functionality

Duplexer (DU) for the separation of transmitted and received signals of a defined frequency band, with an unbalanced antenna port (ANT), a symmetrical output receive (RX-OUT) and a transmission input (TX-IN), with a reception path (RX), which is disposed between the antenna port (ANT) and the receiving output (RX-OUT), a transmission path (TX), which is disposed between the antenna port (ANT) and the transmission input (TX-IN), comprising a receiver bandpass filter (RX-BP), that in the reception path (RX) is arranged and a transmission band-pass filter (TX-BP), which is arranged (TX) in the transmitting path, with one of the characteristics A) or B): A) the receive bandpass filter (RX-BP) comprises a plurality of superposed in the stack, acoustically coupled to one another, working with bulk acoustic wave resonators (RE, RE1), wherein a first resonator (RE1) asymmetrical and a second resonator (RE) symmetrically is wired, B) the receiver bandpass filter (RX-BP) has two sub-filters, a first filter part, a reactance in ladder type, or lattice-type construction with a plurality of operating with acoustic bulk wave resonators (RE, RE1) ...