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Abstract
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This study introduces a new approach for introducing a bidirectional elastic
modulator that operates for acoustic systems in the megahertz frequency range.
The proposed modulator combines a Mach–Zehnder interferometer (MZI) with
a magnetic material within a solid–solid phononic crystal (PnC). In fact, a new
method has been developed to manipulate the interference of acoustic waves
utilizing a magnetic field in a distinctive PnC-MZI configuration. This suggested
modulator is simple and convenient for application in acoustic communication
systems and networks. The PnC structure comprises a square lattice composed
of Tungsten cylinders embedded in a PMMA substrate. The Mach–Zehnder
interferometer consists of two symmetrical arms, with each arm containing an
embedded Terfenol-D material. The proposed modulator operates dynamically by
altering the Young’s modulus of Terfenol-D through the application of an external
magnetic field. By considering three different values of Young’s modulus for the
Terfenol-D hollow cylinders in the two arms, distinct phase shifts for propagating
waves are achieved, resulting in three levels of intensity in the modulator’s output
in the proposed modulator. Another advantage of the proposed configuration
is its bidirectional functionality. Furthermore, the modulator demonstrates a
high extinction ratio of − 22.2 dB and a low insertion loss of 0.4 dB, indicating
its excellent performance. The simulations are fulfilled using the finite element
method.
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