Title :
SAW propagation in complex periodic systems of strips
Author :
Danicki, Eugene J.
Author_Institution :
Polish Acad. of Sci., Warsaw, Poland
Abstract :
The sniper localization exploits a phenomenon of a shock wave generated in air by a supersonic bullet. The characteristic acoustic signal is measured by directional sensors yielding the wave arrival time and its propagation direction at the sensor position, necessary for evaluation of the bullet velocity and trajectory. The solution is sensitive to the measurement errors, depending (in the bullet miss-distance with respect to sensors. SAW devices can improve the measurement accuracy concerning the arrival time and the dependent directional measurements of the shock wave. A class of SAW devices (SPUDT) might be interesting for the sniper localization solution. Complex periodic structures are analyzed here, including several strips per period having different width and spacing, some connected to each other (within a period) or left isolated. A new method is proposed, exploiting the recent theoretical results on electrostatics of multiperiodic systems of strips, yielding the solution to two important cases: for the structure working as a generating or receiving SAW transducer. These solutions help to formulate of the SAW dispersive equation (the analysis is applicable for any surface, transverse or pseudosurface waves) and finally, the useful theory for evaluation and optimization of SAW structures, particularly SPUDT.
Keywords :
acoustic dispersion; acoustic wave propagation; electrostatics; periodic structures; shock waves; surface acoustic wave transducers; SAW devices; SAW dispersive equation; SAW propagation; SAW transducer; SPUDT; arrival time; characteristic acoustic signal; complex periodic structures; complex periodic systems; electrostatics; measurement accuracy; multiperiodic systems; shock wave; sniper localization; strips; supersonic bullet; Acoustic devices; Acoustic propagation; Acoustic sensors; Acoustic waves; Sensor phenomena and characterization; Shock waves; Strips; Surface acoustic wave devices; Surface acoustic waves; Time measurement;
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
Print_ISBN :
0-7803-8412-1
DOI :
10.1109/ULTSYM.2004.1418231