Abstract
This paper presents the first demonstration of chirp compressors based on laterally vibrating modes in suspended lithium niobate thin films. Both shear-horizontal and length-extensional modes have been explored and demonstrated with the electromechanical coupling coefficients of 30% and 39%, respectively, in a double-dispersive delay line structure. The high electromechanical coupling, along with the low propagation loss in the suspended thin film, produces a low insertion loss of 10 dB over a large fractional bandwidth of 50%. The best fabricated device demonstrates a delay-bandwidth product of 100, and provides a voltage gain of 5 to the corresponding chirp signals. Moreover, significant signal-to-noise ratio enhancements (>100), collectively enabled by the processing gain and filtering characteristics of the chirp compressors, have been demonstrated. The measured devices, in this paper, greatly outperform state-of-the-art chirp compressors based on surface acoustic waves in insertion loss for a comparable TB. As a result, signal-to-noise ratio enhancement and voltage gain have been simultaneously demonstrated for the first time in a passive device and the analog domain. The high performance can be harnessed to greatly enhance the sensitivity of near zero power wake-up radio receivers and enable low-power wireless connectivity for Internet of Things applications.
Original language | English (US) |
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Pages (from-to) | 1204-1215 |
Number of pages | 12 |
Journal | Journal of Microelectromechanical Systems |
Volume | 26 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2017 |
Keywords
- Acoustic devices
- Chirp compressors
- Delay lines
- Internet of things
- Lithium niobate
- Low power devices
- Microelectromechanical systems
- Piezoelectricity
- Wake-up radios
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering