A groundbreaking prototype millimeter-wave radar sensor, engineered at the University of California, Davis, has emerged as a potential game-changer in the realm of millimeter wave radars. In a feat of scientific ingenuity, its creators have achieved what they once deemed an “impossible mission.”
Millimeter wave radars harness the power of swiftly moving electromagnetic waves to target objects, deciphering their motion, position, and velocity by analyzing the waves’ reflections. What distinguishes millimeter waves is their remarkable sensitivity to minute motions and their adeptness at gathering data from minuscule objects.
This novel sensor employs an innovative millimeter wave radar design to detect vibrations a thousand times finer and changes in an object’s position one hundred times more subtle than a single strand of human hair. In terms of precision, it rivals or even surpasses the world’s most precise sensors. Remarkably, this diminutive sensor is no larger than a sesame seed, cost-effective to manufacture, and boasts an extended battery life.
The driving force behind this remarkable achievement is Professor Omeed Momeni and his research team in the Department of Electrical and Computer Engineering. This endeavor forms a crucial component of an ongoing project funded by the Foundation for Food & Agriculture Research (FFAR), aimed at creating a low-cost sensor capable of monitoring the water status of individual plants. The newly developed radar sensor represents the pivotal breakthrough that substantiates the feasibility of this project. The findings have been recently published in the IEEE Journal of Solid-State Circuits.
Challenges in Millimeter Wave Technology
Millimeter waves occupy the electromagnetic spectrum between microwaves and infrared, spanning a frequency range from 30 to 300 gigahertz. They enable high-speed communication networks, including 5G, and are prized for their short-range sensing capabilities. However, working with millimeter waves presents its own set of challenges due to their high power consumption and the limited performance of semiconductors at these frequencies.
The primary hurdle the research team faced during the initial year of sensor development was isolating the desired signal amid a sea of noise. The noise levels they needed to contend with were so minuscule that virtually no signal source could effectively handle them.
Momeni recalled, “It seemed truly insurmountable because the noise levels that we were dealing with had to be so exceptionally low that almost no signal source could actually manage it.”
At one point, the researchers questioned whether they could overcome this formidable challenge. Their solution seemed to hinge on creating a radar chip that was ten times more potent and precise than the state-of-the-art design—a task dependent on technological advancements that might still be years away.
A Novel Approach
Sometimes, innovation arises from a fresh perspective on an existing problem. This was precisely the case when Hao Wang, a doctoral student in electrical engineering at Momeni’s High-Speed Integrated Systems Lab, proposed a creative solution to bypass the technological constraints.
Wang’s moment of inspiration involved canceling out noise with noise itself. This ingenious idea offered a theoretical remedy to the sensory inundation they were facing. Wang was on the cusp of completing a chip design for his dissertation, designed to execute precisely this concept.
Wang clarified, “This wasn’t an entirely novel concept plucked out of thin air. It was based on the accumulated research findings we had amassed over the years—then taken a step further through innovation.”
The research team promptly assembled a prototype to test Wang’s concept, and remarkably, it succeeded on the first attempt. The prototype succeeded because it allowed them to treat the noise their sensor encountered as a straightforward arithmetic problem. They subtracted the superfluous noise while preserving the sensitivity of their measurements and the integrity of their data.
This breakthrough technique empowered the millimeter wave sensor to extract all the necessary information without succumbing to noise interference, thereby ensuring high accuracy rates. Furthermore, Wang’s chip design is straightforward to manufacture and features a unique architecture that significantly enhances the energy efficiency of the millimeter wave sensor. These additional advancements may address two of the most pressing issues confronting millimeter wave sensors: excessive energy consumption and the limited performance of semiconductor transistors regarding noise, gain, and output power.
A Future of Boundless Potential
As the research team continues to refine and enhance their design, they eagerly anticipate other researchers’ experimentation with it. Beyond its applications in the FFAR project, they foresee its potential in assessing the structural integrity of buildings and enhancing virtual reality experiences, with untapped potential they are only beginning to comprehend.
Reference: “A Highly Accurate and Sensitive mmWave Displacement-Sensing Doppler Radar With a Quadrature-Less Edge-Driven Phase Demodulator” by Hao Wang, Hamidreza Afzal, and Omeed Momeni, 25 April 2023, IEEE Journal of Solid-State Circuits. DOI: 10.1109/JSSC.2023.3266704.
This study was generously funded by the Foundation for Food and Agriculture Research.
Table of Contents
Frequently Asked Questions (FAQs) about Millimeter-wave Sensor Advancement
What is the key innovation in this millimeter-wave sensor?
The key innovation in this millimeter-wave sensor is its ability to detect vibrations a thousand times smaller and changes in an object’s position one hundred times more subtle than a single strand of human hair, all while being the size of a sesame seed, cost-effective to produce, and boasting an extended battery life.
What challenges did the research team face in developing this sensor?
The research team encountered significant challenges in dealing with minuscule noise levels while developing the sensor. The noise levels were so low that conventional signal sources could not handle them, initially making the task seem nearly impossible.
Who led the development of this millimeter-wave sensor?
Professor Omeed Momeni and his research team in the Department of Electrical and Computer Engineering at the University of California, Davis, led the development of this groundbreaking millimeter-wave sensor.
What practical applications are envisioned for this sensor?
The sensor’s applications extend beyond its initial purpose of tracking the water status of individual plants. It holds promise in areas such as assessing the structural integrity of buildings and enhancing virtual reality experiences, with potential uses that researchers are still exploring.
How was the issue of noise interference resolved in the sensor’s design?
The issue of noise interference was creatively addressed by Hao Wang, an electrical engineering doctoral student, who proposed canceling out noise with noise itself. This approach allowed the sensor to subtract unnecessary noise while preserving measurement sensitivity and data integrity, resulting in high accuracy rates.
More about Millimeter-wave Sensor Advancement
- University of California, Davis
- Foundation for Food & Agriculture Research (FFAR)
- IEEE Journal of Solid-State Circuits
5 comments
Wang’s idea = smart, cancel noise with noise! innov8tion rocks!
High accuracy, low cost, and energy efficient, this sensor has potential galore!
so much noise, team cudnt believe, bt they fix it! wow!
this is amazin, tiny radar like sesame seed, can it really do that?
it track plant water? cool, gd for environment!