Such wide spectral coverage by a single antenna is impossible with a traditional receiver system, say the researchers, and would require multiple systems of individual antennas, amplifiers, and other components. The latest research stems from earlier work on a quantum receiver that uses highly excited, super-sensitive atoms - known as Rydberg atoms - to detect communications signals.
The researchers calculated the receiver's channel capacity - or rate of data transmission - based on fundamental principles, and then achieved that performance experimentally in their lab, improving on the earlier results by orders of magnitude.
“These new sensors can be very small and virtually undetectable, giving Soldiers a disruptive advantage,” says David Meyer, a scientist at the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. “Rydberg-atom based sensors have only recently been considered for general electric-field sensing applications, including as a communications receiver. While Rydberg atoms are known to be broadly sensitive, a quantitative description of the sensitivity over the entire operational range has never been done.”
The scientists conducted an analysis of the Rydberg sensor’s sensitivity to oscillating electric fields over an enormous range of frequencies--from 0 to 10 12 Hertz. The results, say the researchers, show that the Rydberg sensor can reliably detect signals over the entire spectrum and compare favorably with other established electric-field sensor technologies, such as electro-optic crystals and dipole antenna-coupled passive electronics.
“Quantum mechanics allows us to know the sensor calibration and ultimate performance to a very high degree, and it’s identical for every sensor,” says Meyer. “This result is an important step in determining how this system could be used in the field.”
The work supports the Army’s modernization priorities in next-generation computer networks and assured position, navigation, and timing, as it could potentially influence novel communications concepts or approaches to detection of RF signals for geolocation. Looking ahead, the scientists say they will investigate methods to continue to improve the sensitivity to detect