Abstract
The transmission properties of phononic crystal waveguides with grafted stub resonators were measured. The phononic crystal consists of a two-dimensional periodical array of steel rods immersed in water. Waveguides for acoustic waves are created by removing a line defect and stubs are formed by removing rods from the sidewalls of the waveguide. Depending on the stub geometry, definite wavelengths are reflected from the stub creating a one-dimensional bandgap within the waveguide transmission spectrum, the bandwidth of which can be controlled by arranging a proper sequence of stubs. These effects are interpreted as the interaction of propagating waveguide modes with localized stub resonances.