By Matt de Simone
For many Americans, the National Aeronautics and Space Administration (NASA) has always been known to be a United States government organization that oversees space exploration and research related to outer space.
What many Americans (including Botetourt County residents) may not know is that NASA has a friend located in Fincastle.
Micro Harmonics is a Fincastle-based company that specializes in ferrite components for use at millimeter-wave (MMW) frequencies from 25-400 gigahertz (GHz). The company was first established in 2008 by Micro Harmonics CEO David Porterfield and he soon brought in his sister, Micro Harmonics COO and fellow microwave engineer Diane Kees.
Their main product of interest are Faraday rotation isolators. Extremely high frequency electromagnetic signals that rotate inside the magnetized ferrite rod create a phenomenon known as “Faraday rotation.” Faraday rotation was discovered by Michael Faraday in 1845. It was the first experimental evidence that light and electromagnetism are related.
“Radio astronomers use our devices in sensitive systems used to map the universe,” Porterfield explained. “NASA uses our devices in systems that study earth’s atmosphere as well as the atmospheres on other planetary bodies.”
The isolators are a two-port device composed of extremely small parts. A signal comes in one port and goes out without losing power. Any signal that comes in from the other direction gets absorbed internally, like a backflow valve. Combined at a high frequency, the reflections separate the components that don’t like each other, and the isolator smooths the frequencies out.
The core components are as small as a penny or a dime and essential to the business’ success.
Micro Harmonics works in the millimeter wave (MMV) regime. Think: a high-end microwave; low-end infrared—a “no man’s land” due to the difficulty of making things work at such a high frequency level.
The assembly of the isolators requires the Micro Harmonics staff to work with careful precision—all done by hand in their lab located on South Roanoke Street in Fincastle.
“We have some fabricated parts shipped here and we do all of final assembly and testing here,” Porterfield added.
Their isolators are used in satellites, super high-frequency test equipment, and security portals in airports.
“The good thing about millimeter waves is that there’s not a high enough frequency where the photons can’t cause any damage to your body (cells, skin),” Porterfield continued. “It’s not like the high-energy photons in an X-ray or something like that.”
Micro Harmonics sells the isolators all over the globe to companies and countries capable of high-tech industry.
According to Porterfield, Micro Harmonics manufactures the best Faraday rotation isolators money can buy.
“Nobody can beat us on performance,” Porterfield proudly noted. “We’ve developed a reputation that our isolators are the best in the world.”
Through product sales and research and development grants, Micro Harmonics manages to bring new equipment to continue their successful business. Porterfield added that they have good relationships with local companies that help them in isolator development.
Micro Harmonics has new products on the way. They have a new line of voltage variable attenuators—an electronic device that provides a variable attenuation depending on the voltage applied. Unlike fixed attenuators whose attenuation cannot be adjusted by a user, the attenuation levels of variable attenuators can be changed to desired values.
The voltage applied to the device controls the attenuation of voltage variable attenuators. Variable attenuators that are controlled by an application of current are known as current-controlled variable attenuators. These attenuators give the user control over the signal amplitude.
Voltage variable attenuators have a wide variety of applications in radar systems, handset gain control, satellite radios, cellular infrastructure, receiver gain control, general test equipment, temperature compensation circuits, microwave terrestrial links, very small aperture terminals (VSAT), and GSM/EDGE (enhanced data for global evolution) base stations.
They also manufacture ferrite circulators, cornering the market on these communication/radar devices. Their “hybrid circulator” has more bandwidth than common circulators.
Earlier this year, Micro Harmonics won the “Rising Star Award” during the Roanoke Valley’s TechNite event—an event celebrating the leaders, innovators, and successful companies within the regional technology community.
Porterfield expressed his gratitude for Botetourt County government leaders’ interest in Micro Harmonics and their willingness to help out.
“I love it here,” Porterfield mentioned. “The town government and Botetourt County are so helpful to us. They’ve been great.”
For more information on Micro Harmonics, visit their website at mircoharmonics.com.
