Proceedings of the National Academy of Sciences of the United States of America, Vol. 119, No. 8 (February 22, 2022), pp. 1-10 (10 pages) High-frequency (HF) signals are ubiquitous in the industrial ...

Joseph Fourier, born just 250 years ago, introduced a wonderful idea that revolutionised science and mathematics: any function or signal can be broken down into simple periodic sine-waves. Radio waves ...