Abstract
Low-phase-noise microwave-frequency integrated oscillators provide compact solutions for various applications in signal processing, communications, and sensing. Surface acoustic waves (SAWs), featuring orders-of-magnitude shorter wavelength than electromagnetic waves at the same frequency, enable integrated microwave-frequency systems with much smaller footprint on chip. SAW devices also allow higher-quality (Q) factors than electronic components at room temperature. Here, we demonstrate a low-phase-noise gigahertz-frequency SAW oscillator on 128°Y-cut lithium niobate, where the SAW resonator occupies a footprint of 0.05mm2. Leveraging phononic crystal band-gap-edge modes to balance between Q factors and insertion losses, our 1-GHz SAW oscillator features a low phase noise of -132.5 dBc/Hz at a 10-kHz offset frequency and an overlapping Hadamard deviation of 6.5 × 10-10 at an analysis time of 64 ms. The SAW resonator-based oscillator holds high potential in developing low-noise sensors and acousto-optic integrated circuits.
| Original language | English |
|---|---|
| Article number | 024054 |
| Journal | Physical Review Applied |
| Volume | 23 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2025 |
Funding
We thank Professor J. Walling for microwave instrumentation, Dr. S. Ghosh and Dr. M. Benoit for the probe station in the cleanroom for quick tests. Device fabrication was conducted as part of a user project (CNMS2022-B-01473, CNMS2024-B-02643) at the Center for Nanophase Materials Sciences (CNMS), which is a United State Department of Energy Office of Science User Facility. This work is supported by 4-VA Pre-Tenure Faculty Research Award, Virginia Tech FY23 ICTAS EFO Opportunity Seed Investment Grant, 2023 Ralph E. Powe Junior Faculty Enhancement Awards by Oak Ridge Associated Universities (ORAU), and Defense Advanced Research Projects Agency (DARPA) OPTIM program under Contract No. HR00112320031. The views and conclusions contained in this document are those of the authors and do not necessarily reflect the position or the policy of the Government. No official endorsement should be inferred. Approved for public release; distribution is unlimited.