Program Summary
Amplification based on the synchronous interaction between an electromagnetic traveling wave and a monoenergetic stream of electrons is a well-known phenomenon in the field of vacuum electronics and commonly used in devices such as traveling-wave tubes (TWTs). Active gain through traveling wave interaction has been observed or postulated in other domains but has yet to be widely exploited.
The benefits of coupled wave interaction are not limited to THz electronics. Acoustoelectric amplification was first demonstrated in the 1960s. Since then, new piezoelectric materials, device architectures, and fabrication techniques present opportunities to create surface acoustic wave devices with active gain, with advantages ranging from reduced insertion loss to net-positive signal amplification. Spin waves have found application in devices such as frequency selective limiters, phase shifters, delay lines, etc. and more recently are under consideration for nanoscale transmission and processing of information. New techniques using phenomena such as spin-transfer torque and spin-orbit torque show promise to produce spin wave amplification to overcome conversion and propagation losses.
The Traveling-Wave Energy Enhancement Devices (TWEED) Microsystems Exploration (µE) topic aims to develop and demonstrate new approaches using coupled- or traveling-wave interaction to achieve active gain in sub-THz/THz, acoustoelectric, or spin wave devices. The goal of TWEED is to demonstrate proof-of-concept devices that establish the viability of novel approaches that can lead to revolutionary advances in areas such as THz electronics, signal processing, and magnonics. Further, to support potential transitions, the µE emphasizes device architectures and materials that are compatible with current commercial fabrication processes.