Surface acoustic wave diffraction in spectral theory of interdigital transducers

Abstract

A theory of interdigital transducer is presented that accounts for the surface acoustic wave diffraction. It is formulated with help of the Blotekjaer, Ingebrigtsen, and Skeie expansion method used earlier in the plane-wave theory. Now, the electric field is applied to the breaks in the strips making parts of them polarized with different potentials. This way the finite aperture width transducers are modeled residing within an infinite system of periodic strips. Closed expressions are derived for system working below the Bragg condition. The theory is open for further development accounting for elastic strips, pseudo surface, leaky or even surface skimming bulk waves, for any frequency range, including Bragg reflection exploited in surface wave resonators.

Electrostatics of crossed arrays of strips [Correspondence]

“…applying n, m outside the chosen limits results in a trivial solution for the additionally included unknowns [6].…”

“…note that E = E nm is the amplitude of the plane harmonic field varying along the axis ξ, rotated with respect to x,y by angle J, where E(ξ) = E E x y cos s in J J + = E exp (−jk nm ξ), and tan J = s m /r n [6].…”

“…1(a)]. This is a generalization of the BIs-expansion method [4], which was earlier successfully exploited in electrostatic problems [5], the theory of interdigital transducers (IdTs) [6]- [8], and theory of elastic wave scattering by cracks [9].…”

Wave Generation by a Finite Baffle Array in Application to Beam-Forming Analysis

“…(2) stating that the pressure takes given constant values in the slots between baffles, we use a similar technique as described in (Danicki, 2006;Tasinkevych, Danicki, 2005b …”

Efficiency of Ultrasonic Comb Transducers

“…This dependence can be evaluated using the analysis presented in (Danicki, 2006). In the acoustic buffer, spanning from the teeth basis to infinity, the normal incident wave is characterized by particle displacement u I 3 and traction t I 33 = t I 3 , satisfying Eq.…”