Design and implementation of a Rydberg-atom-based quadrature receiver

Image interference is a common issue in heterodyne reception structures, introducing co-channel interference and degrading performance. Although the heterodyne structure significantly improves the sensitivity of the Rydberg-atom-based receiver, the presence of image interference limits its practical application. In this work, we design a quadrature reception structure with a Rydberg-atom-based receiver and experimentally evaluate its performance. This architecture provides orthogonal receiving channels, down-converting input signals into complex form and enabling the separation of image-frequency components. Experiments confirm that conventional heterodyne reception suffers from image interference, while our quadrature structure effectively cancels it after channel compensation. The demonstrated Rydberg-atom-based quadrature receiver shows strong potential for wireless communication and precision measurement, especially in multi-signal environments.