Open AccessGigahertz Low-Loss and Wideband S0 Mode Lithium Niobate Acoustic Delay Lines
Author(s) -
Ruochen Lu,
Tomás Manzaneque,
Yansong Yang,
Ming-Huang Li,
Songbin Gong
Publication year - 2019
Publication title -
ieee transactions on ultrasonics, ferroelectrics and frequency control/ieee transactions on ultrasonics, ferroelectrics, and frequency control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.159
H-Index - 136
eISSN - 1525-8955
pISSN - 0885-3010
DOI - 10.1109/tuffc.2019.2916259
Subject(s) - lithium niobate , wideband , insertion loss , materials science , bandwidth (computing) , transducer , acoustics , surface acoustic wave , optoelectronics , electronic engineering , computer science , telecommunications , physics , engineering
We present the first group of gigahertz S0 mode low loss and wideband acoustic delay lines (ADLs). The ADLs use a single-phase unidirectional transducers (SPUDT) design to launch and propagate the S0 mode in an X-cut lithium niobate thin film with large electromechanical coupling and low damping. In this work, the theoretical performance bounds of S0 mode ADLs are first investigated, significantly surpassing those in state-of-the-art. The design tradeoffs of S0 mode ADLs, when scaled to the gigahertz frequency range, are also discussed. The fabricated miniature ADLs show a fractional bandwidth (FBW) of 4% and a minimum insertion loss (IL) of 3.2 dB, outperforming the incumbent surface acoustic wave (SAW) counterparts, and covering a wide range of delays from 20 to 900 ns for digitally addressable delay synthesis. Multiple ADLs with center frequencies from 0.9 to 2 GHz have been demonstrated, underscoring their great frequency scalability. The propagation properties of S0 waves in lithium niobate at the gigahertz range are experimentally extracted. The demonstrated ADLs can potentially enable wide-range and high-resolution delay synthesis that is highly sought after for the self-interference cancellation in full-duplex radios.