Directional transmission or amplification of microwave signals is indispensable in various applications involving sensitive measurements. In this work we show in experiment how to use a generic cavity optomechanical setup to non-reciprocally amplify microwave signals above 3 GHz in one direction by 9 decibels, and simultaneously attenuate the transmission in the opposite direction by 21 decibels. We use a device including two on-chip superconducting resonators and two metallic drumhead mechanical oscillators. Application of four microwave pump tone frequencies allows for designing constructive or destructive interference for a signal tone depending on the propagation direction. The device can also be configured as an isolator with a lossless nonreciprocal transmission and 18 dB of isolation.
@article{arxiv.1811.06036,
title = {Realization of directional amplification in a microwave optomechanical device},
author = {L. Mercier de Lépinay and E. Damskägg and C. F. Ockeloen-Korppi and M. A. Sillanpää},
journal= {arXiv preprint arXiv:1811.06036},
year = {2019}
}