An all-acoustic filter includes acoustic directional couplers and acoustic filters. In one embodiment, the all-acoustic filter includes two acoustic directional couplers, pair of matched acoustic filters corresponding to either transmit or receive frequency bands, and another acoustic filter corresponding to the other of transmit or receive frequency bands. An all-acoustic duplexer may be realized monolithically in a small form factor, may be tunable, may support multiple transmit or receive frequency bands, or may include schemes for antenna mismatch correction.