Spatial filter-based absorbing boundary for the 2-D digital waveguide mesh

The digital waveguide mesh is a method for simulating wave propagation, for example, in an acoustic system. Research on the boundary conditions has been going on for years, but adequate solutions for absorbing boundaries have not yet been presented for the digital waveguide mesh. In this work, a new method for constructing absorbing boundaries for a two-dimensional (2-D) rectangular mesh is introduced. With the use of the proposed numerically optimized spatial filtering with an interpolated mesh structure, the reflection was diminished to under -25 dB at incidence angles |/spl theta/|/spl les/79.26/spl deg/ on a frequency band limited only at the very lowest and highest ends.