Y-shaped branch structure using asymmetric resonators for phononic demultiplexing

Abstract

In this paper, we present an analytical demonstration of the possibility to realize a simple phononic demultiplexer containing a single resonator. The demultiplexer is a Y-shaped waveguide with an input line and two output lines. Each output line contains a single resonator grafted at a given position far from the input line. We produce the analytical expressions for a selective transfer of a single propagation mode through one line by keeping the other line unaffected. The existence of a complete transmission beside two zero of transmission enables to select a given frequency in the first output line, by canceling the transmission in the second output line and the reflection in the input line. The position and the full width at half maximum (quality factor) of the resonances are sensitive to the geometrical parameters of the proposed phononic system (waveguides and resonators) which should be chosen appropriately. The advantage of the demultiplexer proposed in this study is the simplicity of the device from the technological point of view, where we only need one resonator on each output line. This property is a characteristic of AIT (Acoustic Induced Transparency) resonances and does not exist in standard one-dimensional phononic crystals. The theoretical results are found employing the method of Green function which makes it possible to determine the two transmission rates T1, T2, and the reflection rate R.