Abstract：The microwave quantum precision measurement based on Rydberg electromagnetically induced transparency,due to its advantages of high sensitivity,high resolution,broadband and having direct traceability path to the fundamental physical constant,can be used in various applications,including microwave quantum metrology,communication and imaging.A method for microwave phase shift measurement using rubidium Rydberg atoms is presented here.First, heterodyne reception of signal (SIG) microwave field and local oscillator (LO) microwave field is realized by using hot rubidium Rydberg atomic spectrum, and intermediate frequency (IF) signals with the same phase shift as SIG microwave field are obtained; then the measured signal is processed by the lock-in amplification algorithm to realize the detection of phase difference between the IF signal and a reference signal.The reference signal has the same frequency of IF signal.Finally, while keeping the local microwave field and reference signal unchanged, the phase of the SIG microwave is changed by using the displacement stage, and the microwave phase shift is measured by comparing the phase difference measured at different positions. In order to verify the correctness of the phase shift measurement results,the microwave propagation constant of this frequency is calculated by linear fitting of displacement and the measured phase shift,the relative error of measured microwave propagation constant of 6.92GHz to the theoretical value is within 0.2%. By demonstrating the possibility of microwave phase-shift total optical measurement, the application of microwave quantum precision measurement technology in the field of communication and radar has been laid down.
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2023, Vol. 44 
