2 WAVE-GUIDE TRIFURCATION PROBLEMS

We consider the diffraction of the dominant acoustic wave mode which p ropagates out of the mouth of a semi-infinite waveguide made of a soft and hard half plane. This semi-infinite waveguide is symmetrically lo cated inside an infinite waveguide whose infinite plates are soft and hard. The whole system constitutes a trifurcated waveguide. Another tr ifurcated waveguide is obtained by interchanging the infinite plates. A closed form solution of the resulting matrix Wiener-Kopf equation is obtained for each configuration. Thus we present exact closed-form so lutions to two new waveguide trifurcation problems.