  We in theory proposed a hybrid system consisting of a mechanical resonator,
an optical Fabry-P\'erot cavity, and two superconducting microwave circuits to
generate stationary continuous-variable quantum entanglement between two
microwave modes. We show that the hybrid system can also achieve quantum
entanglement of other bipartite subsystems in experimentally accessible
parameter regimes, which has the potential to be useful in quantum information
processing and quantum illumination radar.
