In complex electromagnetic environments, electronic devices face risks of strong electromagnetic interference, performance degradation and even damage. Accurate acquisition of internal electromagnetic field distribution is a core prerequisite for analyzing field coupling mechanisms, revealing effect principles and evaluating system safety. Traditional metal electric field probes, due to their large size and significant disturbance to the measured field, fail to meet fine measurement needs; electro-optic crystal technology, though having low-disturbance advantage, lacks sufficient sensitivity and frequency selectivity in the GHz band. Rydberg atom-based quantum microwave sensing technology, featuring self-calibration, SI unit traceability and high sensitivity, provides a new solution to the above problems.

This study aims to address the defects of traditional measurement technologies, verify the low-disturbance property of quantum microwave sensing technology, establish an accurate method for measuring internal electric fields of devices, realize high-resolution electromagnetic field distribution mapping, and provide technical support for the analysis and evaluation of complex electromagnetic environment effects.

The FDTD algorithm was used to compare the field disturbance differences between metal probes and Rydberg atomic vapor cells; an experimental system centered on a cesium atomic vapor cell was built, combining electromagnetically induced transparency (EIT) spectroscopy and atomic superheterodyne technology. Forty-five measurement points with 2 cm intervals were set in a square metal shell-simulated device to complete electric field measurement and data processing.

This technology caused minimal disturbance to the measured field, with measurement resolution reaching the millimeter level (less than 2 mm); in the simulated device, the maximum field intensity was 14.62 mV/m and the minimum was 1.66 mV/m. It had better frequency selectivity than electro-optic crystal technology, and low-field measurement could effectively reduce device damage risks.

Quantum microwave sensing technology can make up for the shortcomings of traditional technologies. Although high-field real-time monitoring requires combining with spectrum matching and its instantaneous bandwidth is narrow, its engineering application feasibility has been verified. Future research can focus on developing simplified measurement schemes for high-field scenarios.