US Patent 11100914 Phononic crystal coupler

A phononic coupler. In some embodiments, the phononic coupler includes a sheet, including a plurality of standard reflectors, and a plurality of divergent reflectors. The divergent reflectors define, among the standard reflectors, a first waveguide, and a second waveguide. The coupler has a first port, at a first end of the coupler, a second port, at the first end of the coupler, and a third port, at a second end of the coupler. The first waveguide has a first end at the first port. The second waveguide has a first end at the second port, and a second end at the third port. The coupler is configured to couple longitudinal sound waves to both the first port and the second port.