This paper is devoted to optimization of surface acoustic wave bandpass filters with apodized interdigital transducers (IDT). Iterative Parks-McClellan algorithm is applied to estimate the apodization coefficients of the IDT fingers. A family of corresponding subroutines is developed in the Matlab mathematical package. The simulation results of the SAW filter optimized design are illustrated. For the refined estimation of the filter frequency response COM-based P-Matrices are employed. The results obtained in this study constitute a set of tools for the practical calculation of apodized IDTs and filters according to a given specification. Subroutines implementing COM-based P-Matrices can be utilized as part of programs for frequency-selective SAW devices design.
Keywords: acoustoelectronics, apodization, approximation, interdigitated transducer, impulse response, surface acoustic wave, optimization, piezoelectricity, filter, frequency response
As a result of the work done, the structural features of piezoceramic composites of connectivity 1-3 are determined. Of the various possible methods and materials for piezo-composite electrodes, the only one that is optimally suitable for use in directional ultrasound devices has been selected.
Keywords: piezoceramics, piezocomposite, composite 1-3, piezoelectricity, ultrasound
Vector fields in ocean acoustics are the fields of particle velocity and power flow density. Vector analysis methods are used for theoretical analysis and classification of singular points in a hydroacoustic waveguide. Modeling of the power flow field is carried out as a product of the pressure fields and the components of the velocity particle field. The fields of pressure and velocity particles are calculated by the method of normal modes. The simulation of the power flow field in hydroacoustic waveguides with different sound velocity profiles and different acoustic properties of the bottom is carried out. Some regularities in the location of singular points are revealed.
Keywords: hydroacoustic waveguide, pressure field, particle velocity field, power flow field, singular points