Ultralow-Error and Multifrequency Microwave Photonic Frequency Measurement Based on a Programmable Photonic Processor

Microwave photonic frequency measurement is essential for satellite communication, radar, and electronic warfare systems, providing ultrawide bandwidth and high-precision signal processing. Its superior performance over traditional electronic methods enhances signal detection, antijamming capabilities, and system reliability. However, traditional techniques, including frequency-to-time mapping, photonic-assisted channelization, and frequency-to-power mapping, face limitations in measurement error, complexity, and handling multifrequency signals. Here we introduce a programmable photonic processor for microwave frequency measurement, featuring a large-scale chip with 25 hexagonal cells and 102 programmable units. Our approach uses a two-stage process: Mach–Zehnder interferometers (MZIs) for coarse frequency localization, followed by microring resonators (MRRs) for high-resolution measurement, achieve a root-mean-square error (RMSE) of 9 MHz across 0∼20 GHz. Moreover, an innovative high-dimensional frequency-to-power mapping technique enables the precise measurement of multifrequency signals, effectively overcoming the limitations of traditional methods. These results demonstrate the significant potential of programmable photonic processor to enhance microwave photonic frequency measurement, offering improved performance, flexibility, and scalability for future microwave photonic systems.