ALL-ACOUSTIC DUPLEXERS USING DIRECTIONAL COUPLERS

摘要

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.

主权项

1. A radio frequency (RF) duplexer, comprising:
at least a first port, a second port, and a third port; and a plurality of acoustic components comprising at least:
a first acoustic filter that is coupled to the first port;a second acoustic filter;a third acoustic filter that is substantially similar to the second acoustic filter;a first acoustic quadrature hybrid coupler that is configured to couple signals from the first acoustic filter and the third port to the second acoustic filter and the third acoustic filter; anda second acoustic quadrature hybrid coupler that is configured to couple signals from the second acoustic filter and the third acoustic filter to the second port,wherein the third port is a common port to the first port and the second port,wherein the first port and the second port are isolated, andwherein a transfer function between the first port and the third port and a transfer function between the second port and the third port have passbands at different frequencies as determined by the first acoustic filter, the second acoustic filter, and the third acoustic filter.