AM, or amplitude modulation, was the earliest way of sending voice over radio waves. That makes sense because it is easy to modulate a signal and easy to demodulate it, as well.

This research work, entitled "Spin-dependent amplitude and phase modulation with multifold interferences via single-layer diatomic all-silicon metasurfaces," was published in Volume 4 of Opto ...

Schematic diagram of the proposed photonic generation of ASK microwave signals based on SSB modulation. Credit: Frontiers of Optoelectronics (2023). DOI: 10.1007/s12200-023-00075-2 ...

This hardware is just an Altera MAX10 board, with a single input used for serial data of the audio to be transmitted, and two outputs, each connected to a few bits of wire for a quarter-wave antenna.

University of Twente. "Researchers transmit 10 bit of information with a single photon." ScienceDaily. ScienceDaily, 3 February 2017. <www.sciencedaily.com / releases / 2017 / 02 / 170203102740.htm>.

R = 4800 x 3.32 log (4) = 4800 x 2 = 9600 bits/s If there’s only one bit per symbol, as is the case with binary NRZ, the bit and baud rates remain the same. Multilevel Modulation Techniques ...

News Release 17-Mar-2025 Spin-dependent amplitude and phase modulation with multifold interferences via single-layer diatomic all-silicon metasurfaces ...