Acousto-Electric Signal Processing: Moving Beyond Passive Micro-Acoustic Filters in Piezoelectric/Semiconductor Platforms

Micro-acoustic devices have become an essential part of radio-frequency front-end modules by providing filtering via surface or bulk acoustic waves. Despite their crucial role, these devices are passive and to attain more functionalities such as signal amplification, non-reciprocity, and modulation, they must be integrated with other electronics. For more than sixty years, it has been known that acoustic waves could exchange energy with charge carriers and undergo attenuation or amplification. However, the low energy coupling between the two rendered this scheme impractical. Today, thin-film processing advances have rejuvenated interest in this phenomenon by enabling platforms with high “acousto-electric” energy coupling. Using specific surface or plate waves in piezoelectric/semiconductor heterostructures, promising progress has been made towards realizing amplification and non-reciprocity in the micro-acoustic domain which will be explored in this workshop.