Micro-Resonator Design Implementing Internal Resonance for micro electro-mechanical systems (MEMS) Applications
This invention ensures the consistent frequency of micro electro-mechanical system resonator-based oscillators by using a novel thin-layer stepped beam.
Computer processors are used every minute of every day in phones, cars, computers, TVs, and as the “Internet of Things” expands to refrigerators, toasters, and more processers define how we live our lives. These processors rely on mechanical oscillators and resonators that work together to keep stable frequency references. That stable frequency is used to precisely track time, manage data transfer, and define radio frequencies. Micro electro-mechanical systems (MEMS) resonator-based oscillators show promise over traditional crystal oscillators due to faster responding, lower power consumption, and ability of miniaturization with integrated circuit technology. With micron-sized dimensions, the MEMS oscillators often need to run nonlinearly to obtain large signal-to-noise ratio, which leads to degradation of their frequency stability. At a micro or nano level, MEMS temperature fluctuations, moisture change, absorbing molecules, and small photons will affect frequency stabilization. Therefore, there is a need for a technology to tune and stabilize the frequency of a MEMS oscillator to take advantage of the benefits of MEMS technology.
Researchers at Ohio State University, led by Dr. Han Na Cho, have invented a novel thin layer stepped beam MEMS resonator that can readily implement internal resonance. Internal resonance is a nonlinear mechanism, well known to reduce phase noise by several orders. The thin-layer stepped-beam structure also provides frequency tunability by controlling the mid-plane stretching effect with an applied DC bias. This invention allows processors to take full advantage of micro and nano scale oscillators without sacrificing the quality of the frequency.