Patent of the Month: June 2020

Technology Description

Mechanical resonators are widely used in wireless receivers, bio sensors, and timing and frequency control.  There is considerable interest in industry and academia for ultrahigh precision sensing and fundamental science.  A mechanical resonator, with the following advantages, is desirable for both industrial and academic applications:

1. High quality factor (Q) – frequency products
2. High stability, i.e. consistent performance over time
3. Small Chip-Based Package
4. High tensile stress silicon nitride (SiN) vibrating membrane
5. A periodic support structure provides acoustic isolation
6. Integration compatible with electrical and optical circuits

Our state-of-the-art SiN oscillator has these advantages.  It has a Q – frequency product that is superior to high-stability quartz oscillators.  Its performance is robust to aging and packaging.  Specifically, the invented system has two components:

1. A high tensile stress resonator
2. A periodic supporting substrate that forms an acoustic metamaterial, i.e., phononic bandgap
3. Packaged in one microfabricated chip.

These components make a big impact for replacing quartz crystals.  More than two billion quartz oscillators are manufactured annually.   Most are small devices built for wristwatches, clocks, and electronic circuits, but also used for test and measurement equipment, such as counters, signal generators, and oscilloscopes.  Atomic oscillators are used for applications that require better long-term stability and accuracy. Our acoustically protected SiN resonator is also an enabling element for interfacing optical-to-electrical signal transduction especially in new, emerging “quantum technologies” of the future.

Benefits

High quality factor (Q) – frequency products; high stability, i.e. consistent performance over time; small chip-based package; high tensile stress SiN vibrating membrane; a periodic support structure provides acoustic isolation; and integration compatible with electrical and optical circuits.

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