N-port analysis of a projector consisting of a coaxial array of ferroelectric shells

The coupling between a coaxial array of six ferroelectric shells and its fluid environment is computed by an application of N-port theory. Properties of the lowest ("breathing") mode of the shells are determined by using three-dimensional finite elements, and this knowledge is utilized in defining an N-port representation of the array. An N-port representation of the external fluid is obtained by solving the Helmholtz integral equation that relates fluid velocities and pressure on the exterior of the array. The two N-ports are coupled together in a standard circuit-theoretic manner to produce an equation for the electrical driving-point impedance of the loaded projector. Several frequency responses, which illustrate the effects of varying certain parameters are presented.