Design of a Dual-Frequency Electric Field Local Enhancement Structure for Quantum Microwave Measurements

The quantum microwave measurement technique based on Rydberg atoms has the significant advantages of traceability and self-calibration. To improve the measurement sensitivity of this technique, the electric field local enhancement structure based on microwave resonators has been proposed. However, most electric field local enhancement structures work only at a single frequency. In this letter, a dual-frequency electric field local enhancement structure based on double split-ring resonators is proposed. The simulation results show that the structure achieves 27 and 33 dB enhancement of electric field strength at 1.17 and 1.74 GHz with local enhancement and uniform enhancement of the electric field at the cell, respectively. For experimental tests, it is verified that the structure has an electric field local enhancement effect at dual frequencies by the AC Stark effect and the superheterodyne signal reception method based on Rydberg atoms, effectively improving the sensitivity of quantum microwave measurements.