Digital non-Foster-inspired electronics for broadband impedance matching

• Published in: Nature communications Vol. 15; no. 1; p. 4346
• Main Authors: Yang, Xin, Zhang, Zhihe, Xu, Mengwei, Li, Shuxun, Zhang, Yuanhong, Zhu, Xue-Feng, Ouyang, Xiaoping, Alù, Andrea
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21-05-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/987; 639/766/25/3927; Acoustic resonance; Acoustics; Bandwidths; Broadband; Electroacoustic transducers; Electronics; Humanities and Social Sciences; Impedance matching; Metamaterials; multidisciplinary; Radiators; Resonance; Resonators; Science; Science (multidisciplinary); Transducers; Underwater acoustics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-48861-6

Narrow bandwidths are a general bottleneck for applications relying on passive, linear, subwavelength resonators. In the past decades, several efforts have been devoted to overcoming this challenge, broadening the bandwidth of small resonators by the means of analog non-Foster matching networks for radiators, antennas and metamaterials. However, most non-Foster approaches present challenges in terms of tunability, stability and power limitations. Here, by tuning a subwavelength acoustic transducer with digital non-Foster-inspired electronics, we demonstrate five-fold bandwidth enhancement compared to conventional analog non-Foster matching. Long-distance transmission over airborne acoustic channels, with approximately three orders of magnitude increase in power level, validates the performance of the proposed approach. We also demonstrate convenient reconfigurability of our non-Foster-inspired electronics. This implementation provides a viable solution to enhance the bandwidth of sub-wavelength resonance-based systems, extendable to the electromagnetic domain, and enables the practical implementation of airborne and underwater acoustic radiators.
Resonance-based systems such as electroacoustic transducers are often limited by narrow bandwidth. Here, authors report a digital non-Foster inspired circuit demonstrating significant bandwidth and power level enhancement with greater reconfigurability than conventional analog non-Foster approaches.