An Algorithm for Selecting Transducer Element Array Positions
Abstract
A two-part technique to determine the placement of transducer elements in an array which minimizes the impact of element tolerances on the directional beam pattern has been developed. This technique has been used to place in an array elements with tolerances of + or - 9% in amplitude and + or - 11 deg in phase. The resulting theoretical array response achieved side lobe levels that were within 1 dB of the -40 dB design. The first half of the technique selects four elements at a time from a larger selection pool, and places them in symmetric positions about the center of the array in a manner that partially cancels their respective amplitude and phase variations. The second half of the technique uses a Permutation Search algorithm which rearranges the initial placement of elements in and out of the array looking for improvements in the array response. A lumped-parameter equivalent circuit of a tonpilz transducer is used to predict element amplitude and phase tolerances for different radiation loadings, based on in-air measurements of the transducers. Relationships among the measurable parameters of a transducer and its performance characteristics have been explored. Preliminary estimates of acceptable tolerances for each circuit parameter have been established.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1988
- Accession Number
- ADA196767
Entities
People
- King W. Wiemann
Organizations
- Pennsylvania State University